bluuebunny/crossref_metadata_2025_split huggingface dataset:
DONNAN EQUILIBRIUM AND THE PHYSICAL PROPERTIES OF PROTEINS
Authors: Loeb Jacques 
Published: May 2004

1. It had been shown in previous publications that the osmotic pressure of a 1 per cent solution of a protein-acid salt varies in a characteristic way with the hydrogen ion concentration of the solution, the osmotic pressure having a minimum at the isoelectric point, rising steeply with a decrease in pH until a maximum is reached at pH of 3.4 or 3.5 (in the case of gelatin and crystalline egg albumin), this maximum being followed by a steep drop in the osmotic pressure with a further decrease in the pH of the gelatin or albumin solution. In this paper it is shown that (aside from two minor discrepancies) we can calculate this effect of the pH on the osmotic pressure of a protein-acid salt by assuming that the pH effect is due to that unequal distribution of crystalloidal ions (in particular free acid) on both sides of the membrane which Donnan's theory of membrane equilibrium demands.
2. It had been shown in preceding papers that only the valency but not the nature of the ion (aside from its valency) with which a protein is in combination has any effect upon the osmotic pressure of the solution of the protein; and that the osmotic pressure of a gelatin-acid salt with a monovalent anion (e.g. Cl, NO3, acetate, H2PO4, HC2O4, etc.) is about twice or perhaps a trifle more than twice as high as the osmotic pressure of gelatin sulfate where the anion is bivalent; assuming that the pH and gelatin concentrations of all the solutions are the same.
It is shown in this paper that we can calculate with a fair degree of accuracy this valency effect on the assumption that it is due to the influence of the valency of the anion of a gelatin-acid salt on that relative distribution of the free acid on both sides of the membrane which Donnan's theory of membrane equilibrium demands.
3. The curves of the observed values of the osmotic pressure show two constant minor deviations from the curves of the calculated osmotic pressure. One of these deviations consists in the fact that the values of the ascending branch of the calculated curves are lower than the corresponding values in the curves for the observed osmotic pressure, and the other deviation consists in the fact that the drop in the curves of calculated values occurs at a lower pH than the drop in the curves of the observed values.
STUDIES IN WOOD DECAY
Authors: Schmitz Henry 
Published: May 2004

Circumstantial evidence is presented which indicates that Polyporus volvatus is parasitic.
Cultures of Polyporus volvatus and Fomes igniarius may be obtained from the young sporophores by the tissue method.
In Polyporus volvatus the presence of the following enzymes was demonstrated: esterase, maltase, lactase, sucrase, raffinase, diastase, inulase, cellulase, hemicellulase, glucosidase, rennet, and catalase.
In Fomes igniarius the presence of the following enzymes was demonstrated: esterase, maltase, lactase, sucrase, raffinase, diastase, inulase, cellulase, hemicellulase, glucosidase, urease, rennet, and catalase.
STUDIES ON THE REGULATION OF OSMOTIC PRESSURE
Authors: Palmer Walter W. , Atchley Dana W. , Loeb Robert F. 
Published: May 2004

1. In pure gelatin solutions the conductivity of the solution increases with increasing concentrations, regardless of the hydrogen ion concentration. The actual value of the specific conductivity is greater at that reaction where the degree of ionization is greater.
2. The addition of gelatin in increasing concentrations to a 0.6 per cent sodium chloride solution affects the conductivity of that solution in two ways: (a) At pH 3.3, (where gelatin is highly ionized) the conductivity increases with each added increment of gelatin. (b) At pH 5.1 and 7.4 (where gelatin is less highly ionized) the conductivity decreases with each added increment of gelatin.
A similar study is being made of crystalline egg albumin.
EFFECTS OF CERTAIN LIMITING CONDITIONS ON THE SYNTHESIS OF B VITAMINS BY YEAST
Authors: Eppright Margaret A. , Williams Roger J. 
Published: May 2004

In yeast crops which were grown in the presence of various inhibitors, there was considerable variation in content of the various B vitamins. A higher degree of parallelism in variation in content was found to exist between thiamine and niacin than between any other pair of vitamins; this has been interpreted as indicating that the predominant functions of these two vitamins are their established rôles in fermentation. Values for inositol indicate that it may be involved in fermentation processes, but this is not the case for other members of the B complex. Biotin appears to be unique since in no case did the biotin content of yeast grown in the presence of an inhibitor fall below that of the control yeast. There was some evidence of synthesis of biotin, or a material with biotin activity, in the presence of certain inhibitors, the most striking instance being with sulfaguanidine.
An exogenous supply of biotin was essential for extensive proliferation of F. B. yeast, and yeast grown in a medium to which biotin was the only added vitamin contained the B vitamins in amounts very similar to those found in the control yeast, the most marked differences being in increased vitamin B6 and p-aminobenzoic acid contents.
In the absence of biotin, significant amounts of all of the B vitamins except biotin were synthesized, both in the presence and absence of certain other members of the B complex. The addition of thiamine, pyridoxine, inositol, and ß-alanine to the culture medium caused a reduction in the amounts of vitamin B6 and p-aminobenzoic acid synthesized.
F. B. yeast was able to grow in a xylose medium only when certain of the B vitamins were present, and even then growth was limited. Evidence was obtained for some synthesis of all of the vitamins investigated except biotin and vitamin B6.
The most significant differences in vitamin content between galac yeast and the parent F. B. strain were in folic acid and vitamin B6, the former being considerably reduced in amount, the latter being increased.
OXIDATIVE ASSIMILATION IN RELATION TO PHOTOSYNTHESIS IN CHLORELLA
Authors: Myers Jack ,   With the Technical Assistance of Marian Cramer and James Johnston
Published: May 2004

1. An oxidative assimilation of acetic add and glucose in darkness has been demonstrated in the green alga, Chlorella pyrenoidosa. From manometric experiments it has been shown that 1 mol (CH2O) per mol acetic add and 5 mols (CH2O) per mol glucose are produced.
2. The time required for complete utilization of a limited amount of acetic acid or glucose is not affected by illumination in the absence of carbon dioxide.
3. The time required for complete utilization of a limited amount of glucose is not affected by the simultaneous occurrence of photosynthesis. It must therefore be concluded that the accumulating product of photosynthesis cannot be glucose but must be some slowly respirable (storage) material.
4. Possible interrelationships between oxidative assimilation and photosynthesis may be further studied by following, in darkness and in light, the time course of oxidative assimilation of substrates which are possible intermediates in the two processes.
THE KINETICS OF MULTIPLE ENZYME INHIBITION
Authors: Reiner John M. 
Published: May 2004

The adaptive fermentation of galactose by yeast is inhibited by fluoride and azide. At sufficiently low concentrations, however, it is stimulated.
From a mathematical analysis, using the known fact that fluoride inhibits the enzymes enolase and adenosinetriphosphatase, it is possible to infer the existence of such stimulation. Conditions for this effect are derived which relate the sensitivities of the enzymes to the poison with the rate constants of the various reactions in the fermentation chain.
SOME ASPECTS OF SECRETION
Authors: Osterhout W. J. V. 
Published: May 2004

If we increase the osmotic pressure at one end of a Nitella cell by applying a solution of sucrose and if we subsequently submerge the entire cell in water we find that water enters at the end where the osmotic pressure is higher and comes out of the cell at the other end.
If similar inequalities of osmotic pressure should arise as the result of metabolism we can understand how a secreting cell might take up water at one spot on its surface and expel it in another spot and thus bring about the secretion of water.
The Nitella cell can expel water from a region of the cell which is in contact with water, air, or mineral oil.
BACTERIOPHAGE FORMATION WITHOUT BACTERIAL GROWTH
Authors: Price Winston H. 
Published: May 2004

1. Iodoacetate, fluoride, and azide have been found to prevent the formation of phage and to inhibit the synthesis of ATP by Staphylococcus muscae. It is suggested that energy-rich phosphate is needed for the synthesis of phage.
2. Gramicidin prevented the formation of phage.
3. No differences were found between normal bacteria and phage-infected bacteria in the inorganic phosphate, adenosinetriphosphate, ribonucleic acid, and desoxyribonucleic acid content of the cells.
4. The mechanism of phage formation is discussed.
THE FORMATION AND STABILIZATION OF AN ADAPTIVE ENZYME IN THE ABSENCE OF ITS SUBSTRATE
Authors: Spiegelman S. , Reiner John M. 
Published: May 2004

It is shown that various substrates accelerate the disappearance of an adaptive enzyme when its own substrate has been removed from the medium. The order of effectiveness of such substrates appears to be connected with their chemical similarity to the adaptive substrate.
It is shown that two conditions which are able to inhibit the formation of adaptive enzymes—anaerobiosis and the presence of sodium azide—are equally able to prevent the disappearance of an adaptive enzyme after the removal of its substrate. Finally, it is shown that rapidly growing cultures, under optimal conditions for synthetic activity, are able to maintain and even appreciably to increase their initial content of an adaptive enzyme, in the absence of its specific substrate and in the presence of a normally competitive substrate.
In the light of these results, the three major theories of enzyme formation hitherto proposed are evaluated.
PENETRATION OF RADIOACTIVE SODIUM AND CHLORIDE INTO CEREBROSPINAL FLUID AND AQUEOUS HUMOR
Authors: Wang Jun-Ch'uan 
Published: May 2004

1. Experiments were performed on six dogs to determine the rate of penetration of Cl33 and Na24 across the blood-aqueous humor and blood-cerebrospinal fluid barriers after intravenous injection of the radioactive ions. The radioactivity measurements were made with an immersion type of Geiger-Müller counter.
2. The concentrations of the labelled ions in the anterior chamber and the cisterna magna increase slowly to approach that of plasma. The rate of penetration k is calculated from a simple exponential equation with the half-value interval t0.5 or the time required for the labelled-ion concentration in the fluid to reach 50 per cent of that of plasma. The average t0.5 for Cl38 and Na24 in aqueous humor are 34.3 ± 9 and 27.3 ± 9 minutes, respectively, while those for cerebrospinal fluid are 90 ± 6 and 95 ± 6 minutes, respectively.
3. A study of the radioactivity in plasma was made to determine the per cent remaining after a steady state was reached. By means of this determination the sodium and chloride space was calculated to be 33 ± 5 per cent.
THREE-STAGE ANALYSIS OF BLOOD COAGULATION
Authors: Milstone J. H. 
Published: May 2004

1. Blood-clotting mechanism has been analyzed by a procedure which devotes a separate experimental step to each of the three primary reactions:
1. Prothrombokinase → thrombokinase
2. Prothrombin → thrombin
3. Fibrinogen → fibrin
2. Activation of prothrombin by thrombokinase followed the course of a unimolecular reaction, and the concentration of thrombokinase determined the initial rate. By this relation thrombokinase was measured, and the activation of its precursor was charted.
3. When the activation of prothrombokinase was plotted against time, the experimental points fell close to the theoretical curve for a simple autocatalytic reaction. Moreover, the process was accelerated by seeding with a small amount of crude thrombokinase. It was concluded that the activation of prothrombokinase involves an autocatalytic or chain reaction.
4. The three-stage procedure made possible the separate estimation of the power to activate prothrombin, on one hand, and the capacity to accelerate the transformation of prothrombokinase on the other. Drastic losses of both activities occurred when crude thrombokinase solutions were heated at 60°C., or adsorbed with barium sulfate.
5. The concentration of calcium was important for the normal progress of prothrombin activation, and also for the transformation of prothrombokinase.
SURFACE INACTIVATION OF BACTERIAL VIRUSES AND OF PROTEINS
Authors: Adams Mark H. 
Published: May 2004

1. The seven bacterial viruses of the T group active against E. coli, are rapidly inactivated at gas-liquid interfaces.
2. The kinetics of this inactivation whether brought about by shaking or by bubbling with nitrogen are those of a first order reaction.
3. This inactivation may be prevented by the addition of enough protein to maintain the gas-liquid interface in a saturated condition.
4. The analogy between this phenomenon and the surface denaturation of proteins is pointed out and discussed.
INACTIVATION OF VIRUSES AND CELLS BY MUSTARD GAS
Authors: Herriott Roger M. 
Published: May 2004

The action of mustard gas on six animal, one plant, and two bacterial viruses; also on bacteria, yeast, and the pneumococcus-transforming principle has been studied. The viruses include Newcastle's disease of chickens, equine encephalomyelitis (Eastern strain), feline pneumonitis (Baker), rabbit papilloma (Shope), fixed rabies, rabbit myxoma, tobacco mosaic, T2r+ phage of E. coli B, and a Staphylococcus muscae phage. The cells include bakers' yeast, E. coli B, Staphylococcus muscae, and swine plague bacillus.
The rates of inactivation of the viruses and cells were of the same order of magnitude and faster than those of enzymes.
Of the viruses examined those containing desoxyribose nucleic acid were inactivated faster than those containing ribosenucleic acid. Preparations of the pneumococcus-transforming principle which were largely desoxyribose nucleic acid have shown the greatest sensitivity to mustard gas of all systems examined.
An expression was derived describing the inactivation rate when mustard gas decreases during the experiment.
THE TONICITY-VOLUME RELATIONS FOR SYSTEMS CONTAINING HUMAN RED CELLS AND THE CHLORIDES OF MONOVALENT CATIONS
Authors: Ponder Eric 
Published: May 2004

1. Differences in the fragility of human red cells are observed in equimolar solutions of the chlorides of the monovalent cations. The cells are most fragile in LiCl and least fragile in NaCl, the salts falling in the order Li &gt; K ≧ Rb &gt; Cs &gt; Na.
2. The difference between the tonicity-volume relations in systems containing LiCl and systems containing NaCl lies in the molarity of the solution of LiCl which is isotonic (isoplethechontic) with plasma being considerably greater (0.189 M) than the molarity of the solution of NaCl which is isotonic (isoplethechontic) with plasma (0.160 M). The difference cannot be stated meantime in any simpler terms than these; if the activity coefficients are taken into account, it becomes even greater. The tonicity-volume relations for the two systems are otherwise almost identical; the value of R for the two systems is almost the same, the critical volumes at which the cells of least resistance hemolyze are almost identical, and the critical volumes at which the cells of average resistance hemolyze are almost identical.
3. The LiCl effect on volume occurs as soon after the addition of the cells to 0.172 M LiCl as the hematocrit method allows one to measure it. It is reversible by washing with 0.172 M NaCl.
PHOTOOXIDATIONS IN PIGMENTED BLEPHARISMA
Authors: Giese Arthur C. , Zeuthen Erik 
Published: May 2004

1. Blepharisma undulans, a protozoan with a reddish pigment, shows increased oxygen consumption under the influence of light.
2. If the light intensity is high, the animals are killed during a burst of oxygen consumption.
3. If the blepharismas are first bleached by exposure to light of low intensity they show only slightly increased oxygen consumption under the influence of light and they are not killed.
4. A preparation in which the animals are killed by heat still shows the increase in oxygen consumption on illumination with brilliant light. The supernatant solution does so as well, as does an alcohol extract of the dye.
5. The conclusion is drawn that the blepharismas are killed during photooxidation of the pigment, but the mechanism of action is not clear. Several possibilities are considered in the discussion.
PEPTIDASE INCREASE ACCOMPANYING GROWTH OF THE LARVAL SALIVARY GLAND OF DROSOPHILA MELANOGASTER
Authors: Patterson Elizabeth K. , Dackerman Marjorie E. , Schultz Jack 
Published: May 2004

1. The larval salivary gland of Drosophila melanogaster offers an opportunity to study growth in a tissue in which no cell division occurs but in which the cells increase in size.
2. Measurements of alanylglycine (AG)-peptidase content have been made in three stocks of Drosophila melanogaster at different growth stages of the larval salivary gland, and have been correlated with its total nitrogen and volume.
3. During the prepupal instar, the AG-peptidase content of the gland increases parallel with total nitrogen but decreases when histolysis of the gland begins. Conversely, a benzoyl-l-arginineamide-hydrolyzing endopeptidase is not measurable until histolysis sets in.
4. In the final larval growth period of a giant mutant, there is a concomitant increase in peptidase, total nitrogen, and volume of the gland.
5. A similar association of peptidase content and total nitrogen is found in comparing glands of different sizes from the giant stock, at the time of maximal peptidase content in the prepupa.
6. The data are interpreted as evidence for an association of AG-peptidase with growth of the cells in the gland. This agrees with the earlier interpretation by Linderstrøm-Lang and Holter of data obtained from study of more complex tissues.
7. A survey of the available measurements of peptidase content in other organisms shows that wherever an increase of cell substance occurs, peptidase content increases. Conversely, peptidase remains constant where cell division is unaccompanied by an increase of cell substances.
8. The joint association of peptidases and pentosenucleic acids with protein synthesis is pointed out.
9. The possiblity is considered that peptidases may be essential parts of a unit in which coupled reactions necessary for protein synthesis occur. The rôle of the peptidases in this system is discussed. They may act either synthetically to form new peptide linkages (problematic), or hydrolytically to mobilize the necessary specific amino acids.
METHYL GREEN-PYRONIN
Authors: Kurnick N. B. 
Published: May 2004

1. Methyl green stains selectively highly polymerized desoxyribonucleic acid, and fails to stain, to any significant extent, depolymerized desoxyribonucleic acid and ribonucleic acid.
2. Pyronin stains preferentially low polymers of nucleic acid.
3. Triphenylmethane dyes with two amino groups appear to share the selectivity of methyl green. Those with three amino groups are not selective.
4. A stereochemical hypothesis is offered to account for these observations.
CARBOHYDRATE METABOLISM OF SCHISTOSOMA MANSONI
Authors: Bueding Ernest 
Published: May 2004

1. Schistosoma mansoni utilizes in 1 hour an amount of glucose equivalent to one-sixth to one-fifth of its dry weight. Over 80 per cent of the metabolized glucose is converted to lactic acid by this organism.
2. The rates of glucose utilization and of lactic acid production by S. mansoni are the same under aerobic and under anaerobic conditions.
3. A high rate of lactic acid production and the absence of a postanaerobic increase in the oxygen uptake differentiate S. mansoni from most other parasitic helminths whose metabolism has been studied.
4. Arsenite and p-chloromercuric benzoate inhibit in low concentrations the oxygen uptake and the rate of glycolysis of S. mansoni. This inhibition is not prevented or reversed by an excess of glutathione or of thioglycollate.
5. Fluoride inhibits the removal of glucose and the production of lactic acid by S. mansoni to the same degree.
6. Low concentrations of quinacrine (atabrine) do not affect the respiration or the carbohydrate metabolism of the schistosomes.
7. The inhibitory effect of aldehydes on the metabolism of S. mansoni has been measured. Among this group of compounds dl-glyceraldehyde and o-nitrobenzaldehyde are the most effective inhibitors of glycolysis.
8. In a concentration of 2.6 x 10–6 M (1:1,000,000) a cyanine dye inhibits almost completely the respiration of the schistosomes, but has no effect on their rate of glycolysis. The oxygen uptake of the worms is inhibited by fuadin to a greater degree than their rate of glycolysis. 2-methyl-1,4-napthoquinone is a much more effective inhibitor of glycolysis than of the respiration of S. mansoni. The latter compound interacts with plasma albumin and, therefore, its inhibitory action on the metabolism of the schistosomes is greatly reduced in human serum or plasma.
9. Evidence is discussed which indicates that, in contrast to glycolysis, respiratory metabolism is not essential for the survival of S. mansoni.
STUDIES ON CELL ENZYME SYSTEMS
Authors: Chase Aurin M. 
Published: May 2004

Solutions of the enzyme luciferase, extracted from Cypridina, were subjected at pH 6.8 to temperatures from 40–55°C. for times up to 24 hours. After the desired exposures samples were cooled rapidly to room temperature, mixed with luciferin, and the first order velocity constants (representing luciferase activity) of the resulting luminescent reactions were determined by a photo electric method.
The form of the curve relating luciferase activity to time of exposure to a temperature in the above range is compound in nature. If the exposure to the high temperature is not too long, about two-thirds of the lost activity is slowly regained on standing at room temperature.
The data were described by an equation which represents the following mechanism:
See PDF for Equation
A plot of the logarithm of the rate constant, k1, against the reciprocal of the absolute temperature yielded an experimental activation energy for this reaction of about 57,000 calories, typical of protein denaturation processes. Log k2 plotted against 1/T was described by either a curve or two straight lines, high activation energies resulting in either case, again indicating protein denaturation. The plot of log k3: vs. 1/T showed no apparent dependence upon temperature, k3 being practically constant over the range studied. This may indicate that the underlying mechanism is not actually as simple as pictured. Two other mechanisms that were also considered were discarded because of lack of experimental support.
Measurements of the decrease of luciferase activity at 48°C. and at pH 6.7, pH 5.5, and pH 7.9 showed that inactivation of the enzyme at this temperature was much more rapid at pH 7.9 than at pH 6.7 and was even faster at pH 5.5.
These results from the Cypridina luminescent system were compared with those of other investigators on other systems.