bluuebunny/crossref_metadata_2025 huggingface dataset:
ISOLATION AND CHARACTERIZATION OF THE MAJOR ANTIGEN OF RAT KIDNEY
Authors: Dinh Bao-Linh
Published: December 2009

The major antigen of rat kidney (KMA) was isolated by chromatography on DEAE-cellulose and Sephadex G-25 gel filtration. The sedimentation coefficient of the purified antigen was about 1.2 S and its electrophoretic mobility corresponded to that of α2-globulins. Its diffusion coefficient was estimated by the method of Allison and Humphrey as 11.4 × 10−7 cm2sec−1. On gel filtration through Sephadex G-100, the purified preparation was resolved into two components with identical antigenic properties but of different molecular weights, estimated as 16,600 and 4,100. The concentrations of KMA were determined in different tissues, urine, and serum by immunodiffusion. The probable relationship between physical and immunochemical properties and the possible physio-pathological role of KMA are discussed.
THE HYDROLYSIS OF MONOPHOSPHOINOSITIDE BY EXTRACTS OF BRAIN
Authors: Thompson W.
Published: December 2009

The hydrolysis of monophosphoinositide by soluble extracts from rat brain is described. Diglyceride and inositol monophosphate are liberated along with a small amount of free fatty acids. Hydrolysis of the lipid is optimal at pH 5.4 in acetate buffer. The reaction is stimulated by calcium ions or by high concentration of monovalent cations and, to a less extent, by long-chain cationic amphipathic compounds. Enzyme activity is lost on dialysis of the brain extract and can be restored by diffusible factor(s). Some differences in the conditions for hydrolysis of mono- and tri-phosphoinositides are noted.
BIOSYNTHESIS OF SCOPOLIN IN TOBACCO
Authors: Steck Warren
Published: December 2009

[2-14C]Ferulic acid was fed to tobacco leaves and the radioactive products isolated after 6, 24, and 72 h of metabolism were studied. About half the fed activity was rapidly converted to water-soluble compounds. Feruloylglucose and an ester of ferulic acid glucoside were quickly formed, the former being subsequently incorporated into the fiber and the latter giving rise to scopolin. It is proposed that a ferulic acid glucoside derivative is the natural precursor of scopolin in tobacco.
MITOCHONDRIAL PERMEABILITY AND ATPase ACTIVITY
Authors: Cereijo-Santaló Roberto
Published: December 2009

The hydrolysis of ATP by isolated rat-liver mitochondria has been studied.It was found that gradual disorganization of mitochondrial structure had a biphasic action on ATPase activity similar to that of 2,4-dinitrophenol. Concomitantly a gradual appearance of the magnesium-activated ATPase and disappearance of the 2,4-dinitrophenol-activated ATPase was observed. The disorganization of mitochondria was obtained by preincubation or by treatment with Triton-X-100, n-butanol, oleic acid, or palmitic acid.The pH curves of ATPase activity in sucrose and in KCl media were found to have characteristics similar to those observed in swelling of mitochondria. The equilibrium of the magnesium-activated ATPase reaction depended upon the buffering power of the incubation medium. The activation of the "latent" ATPase by K+, Mg++, Mn++, and Ca++was studied.It is concluded that the "latency" of the ATPase of fresh mitochondria is due to accumulation of protons in the membrane. The removal of these protons by an increased permeability or by exchange with cations activates the "latent" ATPase.
AMINO ACID AND METAL COMPOSITION OF THE α- AND β-LYTIC PROTEASES OF SORANGIUM SP.
Authors: Jurášek L. , Whitaker D. R.
Published: December 2009

Amino acid compositions of two enzymes, α- and β-lytic proteases of Sorangium sp., are reported. The calculated molecular weights and nitrogen contents are in good agreement with experimental values reported previously. A method is described for computing a "best estimate" of the multiplier which converts composition per unit weight of enzyme preparation to composition per mole of enzyme. According to analyses of the performate-oxidized enzymes and of the carboxymethylated enzymes, the α-enzyme has six and the β-enzyme has four half-cystine residues. Titratable sulfhydryl groups could not be detected in either enzyme. The β-enzyme contains one atom of zinc; removal of zinc with o-phenanthroline did not release a titratable sulfhydryl group.
THE PARTITION OF LIPIDS BETWEEN THE YOLK AND YOLK-SAC MEMBRANE DURING THE DEVELOPMENT OF THE CHICK EMBRYO
Authors: Noble R. C. , Moore J. H.
Published: December 2009

A study was made of the concentrations and fatty acid compositions of the various lipid fractions in the yolks and yolk-sac membranes at different stages in the development of the chick embryo. Between the 13th and 17th days of incubation, the transport of lipid from yolk to membrane was so active that on day 17 the yolk-sac membrane contained as much lipid as did the yolk. Free fatty acids, monoglycerides, and diglycerides could not be detected in more than trace concentrations in either the yolk or membrane lipids. Comparisons of the fatty acid compositions and the positional distributions of the various fatty acids in the triglycerides of the yolks and yolk-sac membranes suggested that the major proportion of the yolk triglycerides was absorbed intact by the yolk-sac membrane. There were increases in the esterified : free cholesterol ratios in the yolks and yolk-sac membranes as incubation proceeded but in the membranes, the ratios were markedly greater than those in the yolk. The transport of lipid from yolk to membrane evidently involved extensive esterification of the yolk cholesterol, mainly with oleic acid.
THE EFFECT OF FASTING ON THE ESTERIFICATION OF PALMITATE BY RAT EPIDIDYMAL ADIPOSE TISSUE IN VITRO
Authors: Daniel Anna M. , Rubinstein David
Published: December 2009

The effect of 48-h fasting on the in vitro esterification of fatty acids by rat epididymal adipose tissue was investigated. Fat pads from fed and fasted animals were incubated with palmitate-9,10-3H and glucose-U-14C. Fasting diminished the incorporation of both isotopes into glycerides. The decrease in glucose incorporation after fasting was found both in the glycerol and fatty acid moieties. The effect of fasting was not altered by the presence of insulin. Since lipotysis, which is increased after fasting, results in the preferential hydrolysis of newly synthesized triglycerides, the amount of labeled free glycerol after incubation was determined. It was insufficient to account for the decrease in glucose incorporation into lipids following fasting. The decrease in esterification of palmitate-9,10-3H could also be detected in free adipocytes and fat-free homogenates, but to a less extent than in intact tissue. Esterification by adipose-tissue homogenates from fasted animals was diminished in spite of optimum concentrations of substrates and coenzymes. The decrease in esterification was reflected in both neutral lipids and phosphatidic acid.
THE NATURE OF TWO COMPONENTS OF PIG MUCOSAL HEPARIN, SEPARATED BY ELECTROPHORESIS IN AGAROSE GEL
Authors: Horner Alan A.
Published: December 2009

Two components of pig mucosal heparin were separated by agarose-gel electrophoresis and recovered from the gels. The slower moving component had the higher anticoagulant activity and intrinsic viscosity. The faster moving component had the higher sulfate : carboxyl ratio. Each component was degraded by self-hydrolysis to N-desulfated heparin, deaminated with nitrous acid, and hydrolyzed with formic acid. Two-dimensional electrophoresis and chromatography on thin layers of cellulose showed that each component had two uronic acids with the characteristics of glucuronic and iduronic acids.
RIBONUCLEASE ACTIVITY IN REGENERATING RAT LIVER
Authors: Arora D. J. S. , Lamirande G. de
Published: December 2009

Ribonucleoprotein particles were isolated from sham-hepatectomized and partially hepatectomized animals. The levels of ribonucleic acid and of proteins, as well as the ribosomal ribonuclease activity, have been studied in regenerating liver at periods of 4, 8, 16, 36, and 72 hours after partial hepatectomy. The results showed that the amount of ribosomes in regenerating rat liver was not affected as compared with the level observed in sham-operated rats. However, a decrease of ribonuclease activity was noticed in the early stages of liver regeneration. The ribonuclease activity was practically negligible at 16 and 36 hours. Less than 50% of the enzymatic activity was regained at the 72-hour period after partial hepatectomy.Results show that the ribosomes from regenerating liver are more stable and the stabilizing factor seems to be the absence of ribonuclease.
PURIFICATION OF CA-7, A THROMBOLYTIC FUNGAL PROTEASE
Authors: Ives D. A. J. , Tosoni A. L.
Published: December 2009

Procedures are described for the purification of a thrombolytic fungal protease. These include precipitation with either lignin or tannin, removal of lignin or tannin with acetone, treatment with Benzathine, dialysis, passage through DEAE-Sephadex A-50 and Sephadex G-50, and finally lyophilization. The final product has a molecular weight of about 22,000 and is substantially pure. Amino acid analysis reveals a total absence of cysteine and cystine. The anomalous retention by Sephadex G-50 is discussed.
THE TRANSPORT OF PHOSPHOLIPIDS FROM THE YOLK TO THE YOLK-SAC MEMBRANE DURING THE DEVELOPMENT OF THE CHICK EMBRYO
Authors: Noble R. C. , Moore J. H.
Published: December 2009

A study was made of the concentrations and fatty acid compositions of the various phospholipid fractions in the yolks and yolk-sac membranes at different stages in the development of the chick embryo. Phosphatidyl choline was the major component of both the yolk and membrane phospholipids. The composition of the yolk phospholipids was broadly similar to that of the membrane phospholipids. In both the yolk and membrane phospholipids, the proportions of phosphatidyl choline and phosphatidyl ethanolamine tended to decrease, whereas the proportions of phosphatidyl serine, sphingomyelin, and lysophosphatidyl choline tended to increase as incubation proceeded. The fatty acid composition of the yolk phosphatidyl choline did not change during incubation, but there was a progressive decrease in the palmitic acid: stearic acid ratio in the membrane phosphatidyl choline. The changes in the fatty acid composition of the yolk phosphatidyl ethanolamine indicated that there was a preferential absorption from the yolk of phosphatidyl ethanolamine with stearic acid in the α position and arachidonic or docosahexaenoic acids in the β position. The lysophosphatidyl choline in the yolk and membrane evidently consisted of mixtures of the 1-acyl and 2-acyl isomers. There was no evidence that extensive breakdown and resynthesis of phospholipids occurred during the transport of lipids from the yolk to the yolk-sac membrane.
THE ANTIGENIC LOCI OF INSULIN
Authors: Wilson S. , Aprile M. A. , Sasaki L.
Published: December 2009

Insulin exhibited some cross-reactivity with the isolated S-sulfo A- and B-chains in the passive cutaneous anaphylaxis test. The synthetic peptides A1–9, A10–21, and A1–21gave a passive cutaneous anaphylactic reaction with guinea pig antiserum to natural A-chain, whereas high levels of A10–21and A1–21could also inhibit a subsequent insulin challenge from reacting with antiserum to insulin. The synthetic peptides B1–8, B9–30, B24–30, and B1–30reacted with antiserum to natural B-chain but high levels of peptides (B2–8)2, B9–14, and (B17–23)2were inactive. The symmetrical double peptide (B1–8)2reacted with guinea pig antiserum to intact insulin as well as with antiserum to B-chain and certain sera from insulin-resistant diabetic patients. The results indicated that injection of ox insulin into guinea pigs caused production of anaphylactic antibodies mainly towards antigenic loci in the regions A10–21and B1–8of the insulin molecule, whereas antigenic determinants in the regions A1–9and B24–30were less important.
EFFECT OF COBALT IONS ON MYOCARDIAL METABOLISM
Authors: Wiberg G. S. , Munro I. C. , Morrison A. B.
Published: December 2009

Cobalt treatment (4 mg/kg intraperitoneally for 8 days) significantly depressed the oxygen uptake of rat heart mitochondria incubated in pyruvate, octanoate, and stearate media. Cobalt treatment did not, however, affect oxygen uptake in cardiac mitochondria prepared from thiamine-deficient rats. The addition of α-lipoic acid to the in vitro system greatly enhanced the ability of mitochondria from cobalt-treated rats to metabolize pyruvate. Cobalt treatment in vivo did not appear to exert any inhibitory effect on myocardial succinic dehydrogenase activity.
LIPIDS OF RUST FUNGI: I. LIPID METABOLISM OF GERMINATING FLAX RUST UREDOSPORES
Authors: Jackson Larry L. , Frear D. Stuart
Published: December 2009

Flax rust uredospores were germinated on demineralized water for 8 hours and the changes in total lipid and lipid content were determined at 2-hour intervals. The lipid extracts were fractionated by means of solvent extractions. The amounts of total lipid, non-saponifiable lipid, and lipid phosphorus were determined. Fatty acid compositions of the total lipids and free fatty acid fractions were determined by means of gas chromatography.The total lipid content did not decrease appreciably until after the fourth hour of germination; after 4 hours the rate of decline was more rapid. The non-saponifiable lipids and the lipid phosphorus increased gradually during the 8-hour germination period.During the first 2 hours of germination, about half of the cis-9,10-epoxyoctadecanoate in the glyceride form was hydrolyzed and converted to threo-9,10-dihydroxyoctadecanoic acid, which was found only in the free acid form. Analysis of long chain fatty acids at various stages of germination failed to disclose possible precursors of cis-9,10-epoxyoctadecanoic acid or possible metabolic products from the breakdown of threo-9,10-dihydroxyoctadecanoic acid.
THE PROTEOLYTIC ACTIVITY OF INSULIN
Authors: Page Michel , Godin Claude
Published: December 2009

The action of insulin on hemoglobin at pH 7.5 was studied. Four different methods were used to determine the degree of proteolysis. After mixtures of hemoglobin and insulin were incubated for 2 hours, very little amino acid or peptide material was liberated from the proteins. As many amino acids are liberated from hemoglobin when it is incubated alone under the same conditions. It is concluded that autolysis is responsible for the observed increases in non-protein amino acids and that insulin has no proteolytic activity under the conditions used in this study.
DEHYDROGENASES DURING POSTEMBRYONIG DEVELOPMENT OF TRIBOLIUM CONFUSUM DUVAL (COLEOPTERA): I. MALATE DEHYDROGENASE AND MALIC ENZYME IN THE PARTICULATE AND SOLUBLE FRACTIONS
Authors: Moorjani Sital , Lemonde André
Published: December 2009

Malate dehydrogenase and malic enzyme activities in the particulate (mitochondria) and soluble fraction have been determined in relation to the larval–pupal transformation of Tribolium confusum. The malate dehydrogenase activity in the soluble fraction follows a more or less inverse trend as compared with that in the particulate fraction. The malate dehydrogenase activity in the particulate and soluble fractions of the larva is attributed to different enzymes based on their electrophoretic mobility. A sudden increase in the activity of malate dehydrogenase in the soluble fraction at the end of the larval period is attributed to release of the enzyme from mitochondria by lysis. A further comparison of the larval particulate and pupal soluble malate dehydrogenase is made on the basis of their kinetic behavior. Malic enzyme is NADP-linked, although activity was also noted with NAD. The significance of the high activity of malic enzyme and malate dehydrogenase during pupation is discussed in relation to anaerobic metabolism.
EFFECT OF HYPERVITAMINOSIS A ON INTESTINAL LIPIDS OF RATS
Authors: Misra U. K.
Published: December 2009

The effect of intramuscular administration of retinol (100,000 I.U. daily for 13 days) on intestinal lipids of young rats has been studied. The administration of toxic doses of retinol significantly increased the total lipids of intestine as compared with the control. A significant increase in intestinal monoglycerides, and in phosphatidic acid and polyglycerol phosphatide (present in the phospholipid fraction eluted from a silicic acid column with 5% methanolic chloroform) was observed in the hypervitaminotic A rats. There was no significant difference in the daily food consumption and body weight between the hypervitaminotic A and control rats at the time of sacrifice.
BIOCHEMICAL CHANGES IN PROGRESSIVE MUSCULAR DYSTROPHY: VI. INCORPORATION OF URIDINE-2-14C INTO RNA OF VARIOUS TISSUE OF NORMAL AND DYSTROPHIC MICE
Authors: Srivastava Uma
Published: December 2009

Normal and dystrophic mice were injected intravenously with uridine-2-14C at various stages of the disease. Radioactivity in the acid-soluble fraction of most of the tissues studied was unchanged or not significantly different in dystrophic animals. In vivo incorporation of uridine-2-14C into RNA increased in dystrophic muscle as compared to normal muscle at 30 days, remained the same at 60 days, and was reduced at 90 days. Similar results were also observed on the in vitro incorporation of uridine-2-14C catalyzed by homogenates of normal and dystrophic muscle. Dystrophic brain and pancreas showed a decrease in the incorporation at each stage investigated as compared to controls. No change in the incorporation was noted in dystrophic and normal liver, kidney, spleen, and heart. The decrease in uridine-2-14C incorporation in dystrophic muscle at 90 days could be due to an increased RNA content. Such a phenomenon was explained as due to infiltration of dystrophic muscle by invading macrophages.It is concluded that the metabolism of RNA is not decreased in the dystrophic muscle in preliminary stages of the disease as compared to the control.
THE BINDING OF ETHACRYNIC ACID TO BOVINE SERUM ALBUMIN
Authors: Ronwin Edward , Zacchei Anthony G.
Published: December 2009

Studies with14C-labelled ethacrynic acid indicated that this potent diuretic binds to the albumin fraction of plasma protein. An investigation of the variation of molar binding as a function of the molar concentration ratio revealed that a mole of bovine serum albumin can bind 4 moles of ethacrynic acid strongly (probably irreversibly) and approximately 12 moles reversibly at pH 7.4. Further, it appears that the protein could accommodate a maximum of approximately 16 reversibly bound moles of ethacrynic acid at this pH. Efforts to determine the chemical identity of specific binding sites did not allow positive assignments.
CASTOR BEAN LIPASE: ROLE OF THE LIPID COFACTOR
Authors: Ory Robert L. , St. Angelo Allen J. , deGruy Ines V. , Altschul Aaron M.
Published: December 2009

There is characteristic visual change in the enzyme–substrate particles undergoing lipolysis catalyzed by castor bean lipase. The particles swell, become irregular in shape, and accumulate granular deposits. If the cofactor is not removed from the apoenzyme, these changes can be inhibited by poisoning the enzyme with mercuric chloride without affecting emulsification of the oil substrate, enzyme, and water. It appears that the enzyme is coalesced within the lipid substrate; the composition of this coalesced particle is determined by the relative amounts of enzyme and substrate and by the degree of dispersion. The reaction does not seem to take place solely on the surface, as previously thought.
METHYL ACTIVATION AND sRNA METHYLATION BY SOLUBLE FRACTIONS OF SEVERAL VERTEBRATE LIVERS
Authors: Hancock R. L.
Published: December 2009

The amount of liver ATP: L-methionine S-adenosyltransferase activity varies widely in vertebrates from trace amounts in certain lower vertebrates, e.g. shark or turtle, to relatively large quantities in mammals, e.g. mouse or rabbit. The liver from male mice of a particular stock had only two-thirds the activity of female mouse liver. This difference is not explained by the difference between the sexes in number of X-chromosomes, since female mice with only one X-chromosome (X/0) had the same levels of liver S-adenosyltransferase activity as normal females with two X-chromosomes.sRNA methylase activity from mouse, shark, and rabbit liver supernatant fractions were studied with mouse, shark, and Escherichia coli sRNA. Highspeed supernatant fractions from both rabbit embryonic liver and mouse hepatoma hypermethylated E. coli sRNA which had been previously methylated by adult rabbit or mouse liver supernatant fractions. Hepatoma methylase(s) acts in an analogous manner to that of a species-specific interaction with heterologous and homologous sRNA.A calculation is made comparing the amount of sRNA methylase activity detected in vitro with mouse liver sRNA, with one which is theoretically derived; similar values are obtained. The variation found in vertebrate liver with respect to methyl activation and sRNA methylation is discussed.
FERROUS IRON OXIDATION BY FERROBACILLUS FERROOXIDANS: PURIFICATION AND PROPERTIES OF Fe++-CYTOCHROMEcREDUCTASE
Authors: Din George A. , Suzuki Isamu , Lees Howard
Published: December 2009

The electron transport chain and Fe++-cytochrome c reductase of Ferrobacillus ferrooxidans were studied to elucidate the mechanism of iron oxidation by this autotrophic bacterium.The iron oxidation involved the cytochrome c and a type cytochrome of F. ferrooxidans in the electron transport system. The initial enzyme of the oxidation system was found to be Fe++-cytochrome c reductase. The iron oxidase system was labile to freezing or sonication; either treatment disrupted some link between the cellular cytochromes c and a. Fe++-cytochrome c reductase and cytochrome oxidase retained their individual activities after either treatment.Fe++-cytochrome c reductase was purified 60-fold to 70-fold. The enzyme was judged to be approximately 90% pure by disc electrophoresis, sedimentation, and DEAE-cellulose chromatography. A suitable assay system with a veronal–acetate buffer was developed for the determination of enzyme activity. The effects of inhibitors and potential activators were studied. No specific inhibitor or cofactor was found, although the enzyme was inhibited by various ionic compounds.Fe++-cytochrome c reductase was dissociated into two subunits, one protein and the other ribonucleic acid (RNA). Neither of the subunits had enzymatic activity and efforts to reconstitute the holoenzyme from the two subunits were unsuccessful. The molecular weights of the holoenzyme, protein subunit, and RNA subunit were determined as 100,000–110,000, 27,000–30,000, and 315,000–330,000, respectively. The protein subunit contained one non-heme iron atom per protein molecule. It was concluded that RNA is an essential component of the enzyme and the failure to recover the activity from subunits is due to the aggregation of RNA after dissociation.
MECHANISM OF Fe++-CYTOCROMEcREDUCTASE OF FERROBACILLUS FERROOXIDANS
Authors: Din George A. , Suzuki Isamu
Published: December 2009

The mechanism of Fe++-cytochrome c reductase was investigated. Kinetic studies on initial velocity and product inhibition, as well as spectrofluorometric studies, were consistent with a Ping Pong Bi Bi mechanism with two stable forms of enzyme. The Kmvalues for the substrates were found to be 0.59 mM for Fe++and 0.085 mM for cytochrome c. The inhibition constants for Fe+++and reduced cytochrome c were 0.137 mM and 0.0135 mM, respectively. The oxidation–reduction of non-heme iron bound to the enzyme protein was implicated as the responsible factor for the oscillation of the enzyme between its two forms. NaCl was a dead-end inhibitor binding the ferrous form of the enzyme, showing an uncompetitive inhibition with Fe++as a variable substrate.
SOME CHARACTERISTICS OF BRAIN TYROSINE HYDROXYLASE
Authors: McGeer E. G. , Gibson S. , McGeer P. L.
Published: December 2009

Tyrosine hydroxylase from brain homogenates differed from tyrosine hydroxylase from adrenal homogenates in being particle-bound, insensitive to cofactors, possessing a lower Michaelis constant for tyrosine, and being responsive to slightly different optimum conditions of pH and buffer. The combination of 0.02 M mercaptoethanol and 0.1–1.0 mM 2-amino-4-hydroxy-6,7-dimethyltetrahydropteridine (DMPH4) increased tyrosine hydroxylase activity in beef adrenal homogenates 15-fold, but was without effect on activity in rat brain homogenates. The Kmfor tyrosine in beef adrenal homogenates was 4 × 10−6 M, and in rat brain homogenates was 0.45 × 10−6 M. Conversion in beef adrenal homogenates was maximum in 0.6 M sodium acetate buffer, pH 6.0, and in rat brain homogenates was maximum in 0.28 M phosphate buffer, pH 6.2.
QUANTITATIVE ISOLATION OF PURIFIED ACIDIC GLYCOSAMINOGLYCANS FROM RAT SKIN
Authors: Pearce R. H. , Mathieson J. M.
Published: December 2009

A simple method is proposed for the quantitative isolation of purified glycosaminoglycans from 1- to 3-g samples of rat skin. The cetylpyridinium complex of the polysaccharide is isolated from a clarified papain digest of fresh skin. After recovery of the glycosaminoglycan from the complex, residual protein is removed by treatment, in sequence, with sodium hydroxide, phenol, and trichloroacetic acid. The product contains only small amounts of non-hexosamine nitrogen.The optimal conditions for each step of the procedure were developed by systematic experimentation. The apparent loss of carbazole–borosulfuric chromogen in the formation of cetylpyridinium chloride complex (CPC) seems unlikely to be due to glycosaminoglycan; no other significant losses occurred. The recovery of added glycosaminoglycans was close to theory. The method gave results agreeing well with those for standard published procedures. Trial applications revealed the method to be barely precise enough to distinguish between animals.
DEGRADATION OF AROMATIC AMINO ACIDS BY FUNGI: I. FATE OF L-PHENYLALANINE IN SCHIZOPHYLLUM COMMUNE
Authors: Moore Keith , Towers G. H. N.
Published: December 2009

Growing cultures of Schizophyllum commune could produce 14CO2 from ring-labelled DL-phenylalanine-14C. Intermediates in the pathway of L-phenylalanine degradation prior to ring cleavage were shown to be cinnamic acid, benzoic acid, p-hydroxybenzoic acid, and protocatechuic acid. Phenylacetic acid and L(−)-β-phenyllactic acid were also identified as products of phenylalanine metabolism.
EFFECT OF HEAT TREATMENT ON THE QUALITY AND UTILIZATION BY THE RAT OF PROTEIN IN WHEAT GERM MEAL
Authors: Olsen E. M.
Published: December 2009

Five samples of wheat germ meal (WGM): raw, toasted 45 min, autoclaved 20, 45, or 90 min were analyzed for amino acids. Arginine and lysine were decreased by all treatments; the greatest loss was of lysine in 45- and 90-min autoclaved samples. Digestibility of protein and absorption of amino acids, determined with rats, was decreased by autoclaving. Decreased amino acid content and protein digestibility was reflected in lower weight gain and protein efficiency ratio (PER). Experimentally determined protein digestibilities of mixtures of raw and 90-min autoclaved WGM showed that the digestibility values of the two components were additive. Supplementation of raw WGM with amino acids showed that only methionine improved growth and PER. By these criteria, methionine-supplemented raw WGM was superior to methionine-supplemented soybean meal. Raw WGM exhibited no toxicity for the rat. The results confirm the excellent quality of protein in WGM. It is suggested that heat treatments applied during processing should be kept at a minimum.
ANTIGENICITY OF 5-HYDROXYINDOLE-3-ACETIC ACID, A DERIVATIVE OF SEROTONIN: I. PREPARATION OF PROTEIN CONJUGATES OF 5-HYDROXYINDOLE-3-ACETIC ACID
Authors: Ranadive N. S. , Sehon A. H.
Published: December 2009

5-Hydroxyindole-3-acetic acid (5HIAA) was coupled to human, bovine, and rabbit serum albumins, to bovine γ-globulins, and to ε-aminocaproic acid (ACA) through the formation of peptide bonds. For this purpose N,N′-dicyclohexylcarbodiimide was used to prepare the intermediate acid anhydride of 5HIAA, which was subsequently reacted with the amino groups of proteins or ACA. Evidence is presented for the coupling of (i) about 18 residues of 5HIAA per molecule of albumin, (ii) about 30 residues per globulin molecule, and (iii) 1 residue per molecule of ACA.
PHOSPHONOLIPIDS: XI. SYNTHESIS OF PHOSPHONOLIPID METABOLITES. L-α-GLYCERYL-(2-TRIMETHYLAMMONIUMETHYL)PHOSPHONATE
Authors: Baer Erich , Robinson Ranga
Published: December 2009

The synthesis of a possible intermediate in phosphonolipid metabolism, viz. L-α-glyceryl-(2-trimethylammoniumethyl)phosphonate, a phosphonic acid analogue of L-α-glycerylphosphorylcholine, is described. The compound was obtained by condensation of D-acetone glycerol with (2-bromoethyl)metaphosphonate in boiling benzene, removal of the acetone group of the condensation product by acid hydrolysis, treatment of the hydrolysis product in dimethylformamide with trimethylamine at 60–62° for 3 days, isolation of L-α-glyceryl-(2-trimethylammoniumethyl)phosphate as cadmium chloride complex. Removal of the cadmium chloride was effected with a mixture of Amberlites IR-45 and IRC-50. A procedure for the preparation of (2-bromoethyl)metaphosphonate is reported.
EFFECT OF TEMPERATURE ON METABOLIC RATES OF LIVER AND BROWN FAT HOMOGENATES
Authors: Roberts Jane C. , Smith Robert E.
Published: December 2009

The effects of temperature in vitro upon metabolic rates of homogenates of brown fat and liver from control and cold-acclimated rats have been examined over the range 10–37 °C. At all temperatures, brown adipose tissue exhibits a higher rate of oxygen consumption [Formula: see text] than does liver, α-ketoglutarate being used as substrate. At 10 °C, brown adipose tissue retains a larger percentage (36–38%) of its 37 °C metabolic rate than does liver (22–24%).Q10 values and energies of activation (Ea) have been determined and compared with other data reported for these tissues. At 20 °C, breaks appear in the Arrhenius plots for liver from both control and cold-acclimated rats and also for brown fat from control rats, but not for the brown fat from cold-acclimated rats. Thus brown adipose tissue from cold-acclimated rats retains relatively higher levels of respiration at temperatures below the 20 °C breaking point than does brown fat from control rats.In view of previously reported cold-induced increases in mass, vascularity, and [Formula: see text] of brown fat, this decreased temperature sensitivity in the cold-acclimated rats appears wholly consonant with the adaptive behavior of brown fat in its role as a thermogenic effector.
FURTHER STUDIES ON THE BINDING OF γ-AMINOBUTYRIC ACID BY BRAIN
Authors: Strasberg Paula , Elliott K. A. C.
Published: December 2009

Factors which can interfere with the paper chromatographic – ninhydrin method for determining γ-aminobutyric acid (GABA) are described. The GABA–ninhydrin reaction does not involve loss of CO2. GABA that is occluded in subcellular particles in plain sucrose homogenates of rat brain does not readily exchange with radioactive GABA in solution. The relevant particles are found mostly in the "mitochondrial fraction". These particles deteriorate with time and manipulations, and tend to lose much of their GABA content. The presence of sodium (but not of potassium, calcium, or magnesium) in the suspending medium allows considerably more GABA to be bound. The extra bound GABA is exchangeable with free labelled GABA. Sodium also promotes some exchange between free and occluded GABA. It is concluded from the present and previous results that in brain in vivo very little GABA exists in a freely diffusing situation. There are two forms of bound GABA. One of these is an occluded or storage form which does not readily exchange with free GABA though exchange is to some extent promoted by sodium ions. The other is a form which occurs only in the presence of sodium ion and is freely exchangeable with GABA in solution.
THE TRANSPORT OF CARBON IN WHEAT PLANTS
Authors: McConnell W. B. , Mazurek M.
Published: December 2009

Radioactive tracer experiments indicate that acetate, injected into the top internode of wheat plants, is metabolized during a 24-h period and that it is utilized before translocation from the stem. Movement of tracer was largely toward the head of the plant, the kernel constituents becoming especially radioactive. Free glutamic acid was an early metabolic product of acetate, but protein-bound glutamic acid did not reach a maximum specific activity until between the 1st and 3rd days after injection of the tracer. The maximum specific activity of kernel-protein glutamic acid occurred at about the same time as it exceeded the specific activity of the free glutamic in the kernels. However, the relationship between the specific activities of free and protein-bound glutamic acid of other plant parts was not consistent with the view that the protein glutamic acid was derived solely from a uniform pool of free glutamic acid in the particular plant part being considered.14C incorporated by exposing the head of the wheat plant to14CO2was effectively retained in the head, but extensive transport of14C from the chaff to the kernel was observed. When the leaf of the plant was exposed to14CO2there was extensive respiration of14C Appreciable amounts of14C appeared in the head of the plant and some translocation of tracer to lower stem parts was observed.
PROMOTION OF MYOPATHY BY POLYUNSATURATED FATTY ACIDS OF COD LIVER OIL
Authors: Jenkins K. J. , Ewan L. M.
Published: December 2009

Experiments were conducted to determine the components of cod liver oil responsible for the promotion of nutritional muscular dystrophy in the chick. Supplementation of the dystrophogenic basal diet with 4% of cod liver oil markedly inhibited the protectiveness of selenium and the sulphur amino acids against development of the disorder. Results obtained from feeding various fractions of the oil demonstrated that none of the myopathy-promoting effect was related to the unsaponifiable or saturated fatty acids but was associated chiefly with the eicosapentaenoic (20:5) and docosahexaenoic (22:6) fatty acids. The significance of the results in the development of muscle degeneration is discussed in relation to known effects of dietary lipids and vitamin E deficiency on the composition and stability of cell membrane phospholipids.
THE INFLUENCE OF TUMOR GROWTH ON THE SYNTHESIS OF α2-AP (ACUTE PHASE) GLOBULIN OF RAT SERUM
Authors: Weimer Henry E. , Humelbaugh Constance , Roberts Dorothy M.
Published: December 2009

The effects of growth of the Walker 256 carcinosarcoma on the α2-AP (acute phase) globulin, fibrinogen, seromucoid, and haptoglobin fractions of plasma were investigated in adult, male Sprague–Dawley rats in a longitudinal study. Early increases in α2-AP globulin and seromucoid levels were found to be related to the tissue injury associated with the implantation procedure. Significant elevations in the α2-AP globulin, fibrinogen, and seromucoid fractions coincided with the onset of progressive tumor growth. Serum haptoglobin concentrations exhibited a delayed rise. This was attributed to the in vivo formation of haptoglobin–hemoglobin complexes. It was suggested that the increases in all fractions reflected the release of humoral mediators from injured or necrotic cells wrhich stimulated increased synthesis of the fractions by the liver.
DISTRIBUTION OF TYROSINE HYDROXYLASE ACTIVITY IN ADULT AND DEVELOPING BRAIN
Authors: McGeer E. G. , Gibson S. , Wada J. A. , McGeer P. L.
Published: December 2009

The distribution of tyrosine hydroxylase activity in various areas of brain was studied in mature rats, rabbits, cats, and in kittens of various ages. Distribution was closely similar in all species. Areas known to have high concentrations of catecholinergic nerve endings, such as the caudate, septal area and pineal, showed very high adult levels and sharp increases during the neonatal period. Areas such as the pons–medulla and midbrain, known to contain predominantly catecholinergic cell bodies, showed, on the other hand, relatively low adult levels and little or no change in the neonatal period. Developmental data correlate with known neonatal changes in endogenous catecholamine levels and adult distributions correlate with known turnover rates. The results are in conformity with previous findings that tyrosine hydroxylase is concentrated largely in nerve endings and suggest that measurement of this enzymic activity may provide a more convenient and more sensitive index of catecholinergic nerve activity under various conditions than is provided by measurement of the amines themselves.
EFFECT OF PUROMYCIN ON THE METABOLISM OF PHENYLALANINE IN RATS
Authors: Godin Claude
Published: December 2009

Rats were injected daily with puromycin dihydrochloride. One hour after the puromycin treatment, L-phenylalanine-14C (U) was injected intraperitoneally. The plasma free amino acid concentration was greatly increased in puromycin treated rats. The excretion of 14C in respiratory CO2 was increased and the phenylalanine incorporation into tissue proteins was decreased. No changes in the urinary excretion of radioactivity derived from injected phenylalanine was observed. The increased excretion of 14CO2 derived from injected phenylalanine suggests that the synthesis of the enzymes responsible for the metabolism of phenylalanine is not affected by prolonged treatment with puromycin.
Corticosteroid metabolism in fetal and newborn mice
Authors: Burton A. F. , Jeyes Catherine L.
Published: December 2009

Corticosterone-4-14C was injected intravenously into pregnant mice and fetal tissues were removed after 30 min. Extracts were chromatographed on paper from which zones were eluted and counted. Most counts occurred in the zones representing corticosterone (cpd. B) and 11-dehydrocorticosterone (cpd. A). At a fetal size up to 5 mm crown–rump length (about 11 days), cpd. A constituted 45% of the total counts; this rose as high as 96% (average 80%) in fetuses up to 15 mm. This appeared to be due to increased dehydrogenase activity in fetal tissue; the placenta was also highly active throughout pregnancy. In contrast, late in gestation cpd. A dropped to 24% and this was attributed to the appearance of reductase activity in fetal liver which reduces the metabolite. In young mice for the first 3 weeks of postnatal life the ratio A/B was about 1. Cortisol-4-14C was converted to cortisone but at a slower rate. It was concluded that the 11β-hydroxysteroid dehydrogenase system plays an important role in protecting the fetus from high maternal levels of corticosteroid, but could in some circumstances result in the continued catabolism of biologically active hormone in neonatal life.
An evaluation of the effects of five buffers on respiratory parameters of isolated mitochondria
Authors: Stinson R. A. , Spencer Mary
Published: December 2009

Certain compounds, recently introduced as buffers for biological work in the pH range 6–8, were evaluated by measurement of their effects on mitochondrial respiration. Respiratory control, respiration rate, ADP/O ratio, and the effect of added cytochrome c were measured on bean cotyledon mitochondria, after isolation and incubation of the mitochondria in one of five buffers: phosphate, Tris, Tricine (N-tris(hydroxymethyl)methylglycine), TES (N-tris(hydroxymethyl)methyl-2-aminoethanesulfonic acid), and HEPES (N-2-hydroxyethylpiperazine-N1-2-ethanesulfonic acid). In all parameters measured, except response to added cytochrome c, purified TES was found to be superior to all other buffers. HEPES was the best in prevention of leakage of cytochrome c from the mitochondria but in other respects was similar to Tricine. Phosphate buffer proved superior to Tricine only with respect to cytochrome c retention by the mitochondria. Tris was the poorest buffer in which to measure any of these parameters. Aging the mitochondria in the various buffers amplified the inadequacies of the buffers and served to show the superiority of purified TES.
The chain termini of polynucleotides formed by limited enzymic fragmentation of wheat embryo ribosomal RNA. Part 1. Studies of snake venom phosphodiesterase
Authors: McLennan B. D. , Lane B. G.
Published: December 2009

Snake venom phosphodiesterase induces about fifteen exonucleolytic cleavages for each endonucleolytic cleavage during the first hour of hydrolysis of wheat embryo ribosomal RNA, under the conditions of hydrolysis used in this present investigation. The polynucleotide chains in the ribosomal RNA preparation have an average degree of polymerization in the neighborhood of 1300 nucleotide residues, and there is a mean of between 5 and 10 endonucleolytic breaks per chain during this first hour of phosphodiesterase-induced hydrolysis. The cleavages occur widely throughout most of the polynucleotide chains in the ribosomal RNA preparation, as judged by the sharp decrease in mean sedimentation rate which accompanies a limited degree (about 10%) of exonucleolysis of the RNA. Studies of phosphodiesterase-induced endonucleolysis of wheat embryo soluble RNA are reported, but because of the much lower initial degree of polymerization (about 80 nucleotide residues per polynucleotide chain), the results of endonucleolysis are less pronounced in terms of the proportional increment in chain termini and the proportional decrease of mean sedimentation rate. The endonucleolysis of RNA is discussed in terms of the minor nucleotide components in both ribosomal and soluble RNA, and particular reference is made to pseudouridylate which has been found in relatively high proportion among the chain termini after limited hydrolysis with venom phosphodiesterase.Purified venom phosphodiesterase preparations, devoid of ribonuclease or 5′-nucleotidase contamination, were found to convert nucleoside 2′(3′),5′-diphosphates to 5′-nucleotides under conditions which had virtually no effect on nucleoside 3′-phosphates or nucleoside 5′-phosphates. The possibility that this reaction may be catalyzed by the venom phosphodiesterase itself is discussed.
The subcellular distribution of fatty acid components in ovine heart homogenate
Authors: Neill A. R. , Masters C. J.
Published: December 2009

The lipids of the subcellular fractions of ovine heart homogenate have been separated by chromatography on silicic acid into cholesteryl ester, glyceride and free fatty acid, and phospholipid fractions. Gas–liquid chromatography was used to determine the fatty acid compositions of these fractions.In all the subcellular organelles, phospholipid was the major lipid class, but in the cell sap fraction, glycerides predominated.By means of this lipid fractionation, and the presence in this tissue of two unusual major components, it has been possible to demonstrate a differential distribution of fatty acids between the separate subcellular fractions. The significance of this finding has been discussed in relation to the functions of lipids, the processes of fatty acid desaturation in the cell, and membrane biochemistry.The phospholipids of ovine mitochondria have been shown to be markedly saturated by comparison with the properties of this fraction in other mammals, and the implications of this lack of polyunsaturated components are considered in the Discussion.
Suppression of hepatic cholesterogenesis in the rat by lithium ion
Authors: Leal R. S. , Lyra M. L. M.
Published: December 2009

The effects of lithium ion on the rates of incorporation of acetate-1-14C and mevalonic-2-14C acid into cholesterol, on 14CO2 production and acetoacetate formation from carboxyl-labeled acetate, on serum and liver cholesterol levels, and on the acetate-activating system were studied in rat liver.It has been found that while the incorporation of labeled acetate into cholesterol was strongly suppressed by lithium ion, incorporation of mevalonate into cholesterol under the same conditions was virtually unchanged. It thus appears that lithium ion produces its effect prior to the formation of mevalonic acid in the pathway of cholesterol biosynthesis.Liver cholesterol levels are practically unchanged after 4 weeks' treatment with lithium chloride while serum cholesterol, under the same conditions, appears to be slightly increased in the treated animals. 14CO2 production and acetoacetate formation from carboxyl-labeled acetate, and the acetate-activating system of rat liver appear to be slightly impaired by lithium ion. The possibility of the existence of more than one block between acetate and mevalonic acid on the cholesterol biosynthetic pathway is discussed.
Agents affecting lipid metabolism. XXXI. Properties of an inhibitor of cholesterol synthesis present in rabbit liver mitochondria
Authors: Cayen M. N. , Dvornik D.
Published: December 2009

Aqueous extracts of mitochondria from livers of starved animals have been reported to inhibit hepatic cholesterol synthesis. Some properties of a mitochondrial extract prepared from starved rabbits have been studied. The extract depressed the incorporation of both 2-14C-acetate and 3H-mevalonate into cholesterol by rat liver homogenates, giving concentration–dependent responses. The active factor was unstable to heat, but stable under in vitro incubation conditions, to pH changes, and to storage in the dark and cold. It was cationic and associated with one or more large molecules (mol. wt. 50 000–150 000); it was not cleaved by trypsin digestion. Fractionation experiments did not result in any significant enrichment of inhibitory activity.
Lipids of the fin whale (Balaenoptera physalus) from North Atlantic waters. IV. Fin whale milk
Authors: Ackman R. G. , Eaton C. A. , Hooper S. N.
Published: December 2009

Fatty acid compositions were determined for total lipid (17.5% of the milk and > 95% triglycerides), 2-monoglyceride obtained by enzymatic hydrolysis of isolated triglyceride, and isolated phospholipid (~1% of total lipids). The total lipid fatty acids of the milk had a composition similar to fin whale depot fat but were enriched in hexadecanoic acid and polyunsaturated fatty acids at the expense of monoethylenic acids; correspondingly the iodine value of 136 (methyl esters) was higher than the normal range (105–120) of North Atlantic fin whale blubber oils. Over 80% of the fatty acids in the 2-position of the triglycerides were accounted for by relatively short chain fatty acids, especially hexadecanoic (54.6%), tetradecanoic (13.7%), and hexadecenoic (11.2%), so that the ester iodine value was only 48. The milk phospholipids had a fatty acid composition basically similar to that of liver phospholipids (methyl ester iodine value 120) with somewhat more polyunsaturated fatty acids and accordingly an iodine value of 144 for methyl esters.
Composition of milk cephalins
Authors: Moore G. M. , Rattray J. B. M. , Irvine D. M.
Published: December 2009

Lipid was extracted from lyophilized samples of cow, goat, sheep, horse, and human milk. The cephalins were isolated by thin-layer chromatography and ascertained to be the major, but variable component of all milk phospholipids examined except in the case of the horse. The predominant cephalin type was found to be phosphatidyl ethanolamine (PE), while phosphatidyl serine (PS) was determined to be either absent or to account for approximately 20% of the total cephalins. Lysocephalins were generally absent. The fatty acid composition of PE and PS was characterized by high levels of oleic and palmitic acids and by the virtual lack of long-chain polyunsaturated fatty acids. Individual differences in fatty acid content were slight among members of the same species, but human milk PE showed considerable variations in composition. PE was determined to be more highly unsaturated than PS with the unsaturated fatty acids occurring primarily at the β-position of the PE molecule. The results obtained on the chemical structure of milk cephalins have been discussed in relationship to the suggested activity of these compounds on the blood coagulation process in vitro.
The effect of metals on the binding of 131I-labelled acid-soluble protein to myelin in vitro
Authors: Moscarello M. A. , Murdoch D. , Wood D. D.
Published: December 2009

An encephalitogenic protein was extracted from myelin and labelled with 131I. The binding of this radioactive protein to myelin was measured in vitro. It was found that Cu++ enhanced the binding, but that Al+++, Ca++, Mg++, Zn++, Mn++, Na+, and K+ did not. After binding, the radioactive protein was extracted from myelin and shown to be identical with the original protein.