bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining Ability, Heterosis and Gene Action for Grain Yield and Its Related Traits of Some WA-CMS with Tester Lines of Rice (Oryza sativa L.)
Authors: Yousef M. I. Abo- , Ghidan W. F. , Talha I. A. , Elsehely A. B. , Tabl Dalia M.
Published: December 2020

An understanding the nature and relative extent of gene actions and combining ability is useful for a breeder to develop superior rice hybrids. In this association, an attempt was made to identify good general and specific combiners for selecting better parents and better cross combinations for developing high yielding and short duration rice hybrids. Four cytoplasmic male sterile lines viz., IR69625A, IR70368A, IR58025A and IR79575A were crossed with ten elite testers, 40 hybrids along with their fourteen parents were evaluated for grain yield and its related traits at the experimental farm of Rice Research and Training Center, Sakha, Kafr El-Sheikh, Egypt, during the rice-growing seasons of 2018 and 2019. The differences among genotypes, parents and crosses were highly significant for all studied traits. The specific combining ability (SCA) played the major role in determining inheritance traits, revealing that the largest part of the total genetic variability associated with most traits was a result of non-additive gene action. The parental line, IR58025A was demonstrated as a great general combiner for grain yield per plant and most of yield components and therefore could be utilized in future breeding programs to improve grain yield. HHZ12-SAL8-Y1-SAL1, HHZ5-Y7-Y2-SUB1 and HUA564 were seen as a good general combiner among testers for grain yield per plant and some studied traits. Four crosses, namely IR58025A / HHZ8-SAL9-DT2-Y2, IR70368A / WEED TOLERANT RICE1, IR70368A / HHZ12-SAL8-Y1-SAL1 and IR70368A / HHZ5-Y7-Y2-SUB1 exhibited significantly good specific combining ability effects for grain yield per plant. Hence, it can be seen that non-additive genetic effects are controlling the inheritance of the studied traits and indicated that selection for the traits inherited with this manner should be performed in the further generations.
Identification of the NH2‐terminal blocking group of calcineurin B as myristic acid
Authors: Aitken Alastair , Cohen Philip , Santikarn Sitthivet , Williams Dudley H. , Calder A.Graham , Smith Alistair , Klee Claude B.
Published: July 2002

The NH2‐terminal blocking group of the Ca 2+‐binding B‐subunit of calcineurin (protein phosphatase‐2B) has been identified as myristic acid by fast atom bombardment mass spectrometry and gas chromatography. The sequence, myristyl‐Gly‐Asn‐Glu‐Ala‐, is very similar to that of the catalytic subunit of cyclic AMP‐dependent protein kinase, the only other protein known to contain this fatty acid. This finding, and the elution of all myristyl peptides at 57% acetonitrile on reverse phase HPLC, may facilitate the identification of other proteins with this blocking group.
Stimulation by thyrotropin and cyclic AMP of the proliferation of quiescent canine thyroid cells cultured in a defined medium containing insulin
Authors: Roger Pierre P. , Servais Patricia , Dumont Jacques E.
Published: July 2002

We have developed serum‐free primary cultures of differentiated follicular dog thyroid cells which allow the study of the hormonal control of cell proliferation. The cooperation of insulin and increasing cellular cyclic AMP by thyrotropin triggers the DNA synthesis and the proliferation. Dog thyroid cells are an example of a system in which cyclic AMP is a sufficient signal to stimulate the proliferation in quiescent cells.
Uncoupling protein in human brown adipose tissue mitochondria
Authors: Lean M.E.J. , James W.P.T.
Published: July 2002

A protein of M
r 32000 has been isolated from human infant brown adipose tissue mitochondria following the procedure used to purify the uncoupling protein from rat brown adipose tissue mitochondria. A specific antiserum has been raised against the human 32 kDa protein, and used to detect it by probing mitochondrial proteins separated by SDS—PAGE. The protein is present in large amounts in brown adipose tissue but is undetectable in human liver, heart or white adipose tissue. It has strong immunological cross‐reactivity with rat brown adipose tissue uncoupling protein.
The primary structure of protein S14 from the small ribosomal subunit of Escherichia coli
Authors: Yaguchi M. , Roy C. , Reithmeier R.A.F. , Wittmann-Liebold B. , Wittmann H.G.
Published: July 2002

Protein S14 was isolated in pure form from Escherichia coli ribosomal 30 S subunits. Its complete amino acid sequence was determined by a combination of various approaches, such as enzymatic and chemical cleavage of the protein chain, isolation of the resulting peptides as well as manual and automatic sequence determination by the Edman degradation technique. The protein has an M
r of 11 191 and consists of 98 amino acid residues, 26 of which are basic and 9 acidic. One residue each of cysteine, histidine, tyrosine and tryptophan is present in the protein. The secondary structure of protein S14 as predicted according to 4 different programs shows a long α‐helix in the N‐terminal region and a short α‐helix near the C‐terminus of the protein chain. When the amino acid sequence of protein S14 was compared with that of all other E. coli ribosomal proteins with computer search programs, only relatively short homologous regions were found. A comparison between protein S14 of E. coli and the homologous protein from Bacillus stearothermophilus revealed ∼35% identity within the protein regions available for comparison.
Effect of pH on the photoreaction cycles of bacteriorhodopsin
Authors: Kobayashi Takayoshi , Ohtani Hiroyuki , Iwai Jin-ichi , Ikegami Akira , Uchiki Hisao
Published: July 2002

Photoreaction cycles of acidified bacteriorhodopsin (bRacid
605) at room temperature was studied by nanosecond and picosecond spectroscopy. A precursor of bathobacteriorhodopsin was found to be converted to bathobacteriorhodopsin within 30 ps. Spectra and formation times of batho‐ and lumibacteriorhodopsin are identical to those of bacteriorhodopsin in neutral suspension. However, lumibacteriorhodopsin lifetime is > 700 μs and the formation of metabacteriorhodopsin was not observed in low pH suspension. Thus, the decay process of lumibacteriorhodopsin plays an important role in the proton pump action.
Increase of proton electrochemical potential and ATP synthesis in rat liver mitochondria irradiated in vitro by helium‐neon laser
Authors: Passarella S. , Casamassima E. , Molinari S. , Pastore D. , Quagliariello E. , Catalano I.M. , Cingolani A.
Published: July 2002

Mitochondria
Laser
Transmembrane proton gradient
Membrane potential
ATP synthesis
Oxygen uptake
Association of ferredoxin‐NADP+ oxidoreductase with the chloroplast cytochrome b‐f complex
Authors: Clark R.D. , Hawkesford M.J. , Coughlan S.J. , Bennett J. , Hind G.
Published: July 2002

The 37‐kDa non‐heme component in spinach cytochrome b‐f complex prepared from EDTA‐washed thylakoids [(1983) J. Biol. Chem. 258, 10348‐10354] is shown to be ferredoxin‐NADP+ oxidoreductase (EC 1.18.1.2) on the basis of immunoreactivity, amino acid analysis, and pattern of cleavage by cyanogen bromide. Strong binding of the reductase to the isolated cytochrome complex suggests this is an important site for its attachment to the thylakoid membrane in vivo.
Binding of interleukin 2 to gangliosides
Authors: Parker Judy , Caldini Gabriella , Krishnamurti Chitra , Ahrens Patricia B. , Ankel Helmut
Published: July 2002

Exogenous gangliosides inhibit interleukin 2 (IL2)‐dependent growth of a T cell line, AKIL‐1.E8. IL2 activity is retained by columns of ganglioside covalently linked to poly(L‐lysine)‐agarose and is not eluted with ethylene glycol but is completely recovered by elution with 1% SDS. The ability of gangliosides to inhibit IL2 activity is directly related to the complexity of their carbohydrate portion, and related ceramide derivatives at similar concentrations do not inhibit IL2 activity. We conclude that IL2 bound to exogenous gangliosides is inactive and that the carbohydrate portion of the ganglioside is crucial to its interaction with IL2.
Ricinus communis agglutinin B chain contains a fucosylated oligosaccharide side chain not present on ricin B chain
Authors: Lord J.Michard , Harley Suzanne M.
Published: July 2002

Ricinus communis agglutinin
Ricin
B chain
Fucose
Use of monoclonal antibodies to analyse the expression of a multi‐tubulin family
Authors: Birkett Christopher R. , Foster Kay E. , Johnson Lawrence , Gull Keith
Published: July 2002

We have used a panel of monoclonal antibodies in a study of the expression of multiple tubulins in Physarum
polycephalum. Three anti‐β‐tubulin monoclonal antibodies, DM 1B, DM3B3 and KMX‐1 all reacted with the β1‐tubulin isotypes expressed in both myxamoebae and plasmodia. However, these antibodies showed a spectrum of reduced reactivity with the plasmodial β2‐tubulin isotype ‐ the competence of recognition of this isotype was graded DM1B > KMX‐1 > DM3B3. The anti‐α‐tubulin monoclonal antibody, YOL defined the full complement of Physarum α‐tubulin isotypes, whilst the anti‐α‐tubulin monoclonal antibody, KMP‐1 showed a remarkably high degree of isotype specificity. KMP‐1 recognises all of the myxamoebal α1‐tubulin isotypes but only recognises 3 out of the 4 α1‐tubulin isotypes expressed in the plasmodium (which normally focus in the same 2D gel spot). KMP‐1 does not recognise the plasmodial specific α2‐tubulin isotype. This monoclonal antibody reveals a new level of complexity amongst the tubulin isotypes expressed in Physarum and suggests that monoclonal antibodies are valuable probes for individual members of multi‐tubulin families.
Requirements for the photoligation of Mn2+ in PS II membranes and the expression of water‐oxidizing activity of the polynuclear Mn‐catalyst
Authors: Tamura Noriaki , Cheniae G.M.
Published: July 2002

Ligation of Mn2+ into the polynuclear Mn‐catalyst of water oxidation was shown using PS II membranes depleted of their Mn and the 17, 23 and 33 kDa extrinsic proteins. This process specifically required light and Ca2+ concentrations of 5̃0 mM. Evidence was obtained indicating Mn2+/Ca2+ competition for Ca2+ and Mn2+ binding sites essential for the photoligation of Mn. Photoligation of Mn did not result in an increase of water oxidation capacity; however, water oxidation capacity was expressed following dark reconstitution minimally with the 33 kDa protein. The results represent the first observation of photoactivation of water oxidation in a system that excludes simple light‐driven Mn2+ transport across membrane(s).
Carbachol and oxytocin stimulate the generation of inositol phosphates in the guinea pig myometrium
Authors: Marc Sylvie , Leiber Denis , Harbon Simone
Published: July 2002

In the guinea pig myometrium prelabelled with myo‐[2‐3H]inositol, carbachol and oxytocin enhanced a concentration‐dependent and rapid release of IP3 which preceded that of IP2 and IP1. The specific receptor‐mediated phospholipase C activation degrading PIP2 to IP3 did not require the presence of extracellular Ca2+. The ionophore A23187 as well as K+ depolarization failed to increase inositol phosphate accumulation. It is proposed that IP3 could have a role in the contraction of uterine smooth muscle elicited by the activation of muscarinic as well as of oxytocin receptors.
Why mitochondria need a genome
Authors: von Heijne Gunnar
Published: July 2002

The evolution of the mitochondrial genome towards the compact organization found in the higher eukaryotes is discussed. It is suggested that the machinery for co‐translational protein export across the endoplasmic reticulum membrane sets strict limits on the kinds of protein‐coding genes that can be successfully transferred from the mitochondrial to the nuclear genome. This hypothesis is in perfect agreement with the pattern of mitochondrially vs nuclearly encoded mitochondrial proteins found in species such as man, mouse, and Xenopus.
The role of adenine nucleotide translocators in regulation of oxidative phosphorylation in heart mitochondria
Authors: Kholodenko B. , Z̆ilinskie·e V. , Borutait·e V. , Ivanovien·e L. , Toleikis A. , Pras̆kevic̆ius A.
Published: July 2002

The regulative role of adenine nucleotide translocators (ANTs) in oxidative phosphorylation has been estimated by the titration of respiration of isolated rabbit heart mitochondria with carboxyatractyloside in the presence of a non‐rate limiting creatine phosphokinase ADP‐regenerating system. It has been established that the respiration rate is not controlled by ANTs in the two extreme states, state 3 and state 4. On the other hand, at an intermediate respiration rate (30–70% of the state 3 respiration, which roughly corresponds to that under physiological conditions) the ANT control coefficient had a value of 0.62–0.75. Thus, ANTs seem to play a key role in the regulation of oxidative phosphorylation.
Rapid changes of heat and desiccation tolerance correlated with changes of trehalose content in Saccharomyces cerevisiae cells subjected to temperature shifts
Authors: Hottiger Thomas , Boller Thomas , Wiemken Andres
Published: July 2002

The trehalose content of exponentially growing Saccharomyces cerevisiae cells rapidly increased in response to a temperature shift from 27 to 40°C and decreased again when the temperature was shifted back from 40 to 27°C. These changes were closely correlated with increases and decreases in the thermotolerance and desiccation tolerance of the cells. Our results support the hypothesis that trehalose functions as a protectant against heat and desiccation.
The amino acid sequence of toxin RpIII from the sea anemone, Radianthus paumotensis
Authors: Metrione Robert M. , Schweitz Hugues , Walsh Kenneth A.
Published: July 2002

The amino acid sequence of the sodium channel toxin RpIII from the sea anemone Radianthus paumotensis has been determined. The protein is homologous with five analogous toxins from three anemone species and is most similar to a less toxic protein, RpII, from the same organism. Twelve residues are conserved in all six toxins, one of which is an arginine residue thought to be essential for toxicity. The others (Cys, Gly, Pro and Trp) tend to be conserved in other sets of homologous proteins to maintain functional folds. Comparisons of the sequences suggest the existence of two separate but related classes of toxins cumon the three species of anemone.
Phagocytic cells metabolize 25‐hydroxyvitamin D3 to 10‐oxo‐19‐nor‐25‐hydroxyvitamin D3 and a new metabolite, 8α,25‐dihydroxy‐9, 10‐seco‐4,6,10(19)‐cholestatrien‐3‐one
Authors: Hayashi Takamune , Yamada Sachiko , Miyaura Chisato , Tanaka Hirofumi , Yamamoto Keiko , Abe Etsuko , Takayama Hiroaki , Suda Tatsuo
Published: July 2002

The metabolism of 25‐hydroxyvitamin D3 [25(OH)D3] was examined in several phagocytic cells including alveolar macrophages and myeloid leukemia cells (M1, HL‐60 and U937). Phagocytic cells converted 25(OH)D3 to 10‐oxo‐19‐nor‐25‐hydroxyvitamin D3 and a new metabolite. The former metabolite was dominant in shorter incubation periods (1 h), whereas the latter dominated over longer incubation periods (24 h). The new metabolite was produced from 25(OH)D3 directly but not through 10‐oxo‐19‐nor‐25‐hydroxyvitamin D3. The new metabolite was unequivocally identified as 8α,25‐dihydroxy‐9,10‐seco‐4,6,10(19)‐cholestatrien‐3‐one. These results suggest that phagocytic cells somehow promote oxidation of the triene part of vitamin D compounds.
Fluorescent probe studies on binding of glyceraldehyde‐3‐phosphate dehydrogenase to phosphatidylinositol liposomes Further evidence for conformational changes
Authors: Michalak Krystyna , Gutowicz Jan , Modrzycka Teresa
Published: July 2002

Glyceraldehyde‐3‐phosphate dehydrogenase from rabbit muscle can be adsorbed on charged lipid bilayers by electrostatic forces. Upon binding to phosphatidylinositol liposomes the enzyme modifies its conformational state as it is shown by resonance energy transfer experiments. In the presence of 2‐mercaptoethanol o‐phthaldialdehyde reacts with amino groups of the protein and the covalently bound fluorophore is an acceptor of excitation energy transferred from tryptophanyl residues of the protein. The observed decrease of energy transfer efficiency upon binding to phosphatidylinositol liposomes is compared with the influence of the urea on the fluorescence spectra of the labelled protein. Significance of conformational changes of the enzyme upon adsorption on liposomes in the regulating function of cell membranes is discussed.
Proposal that the function of the membrane‐bound cytochrome a1‐like haemoprotein (cytochrome b‐595) in Escherichia coli is a direct electron donation to cytochrome d
Authors: Poole Robert K. , Williams Huw D.
Published: July 2002

The cytochrome d‐containing oxidase of oxygen‐limited Escherichia coli comprises cytochromes d, cytochrome b‐558 and cytochrome b‐595, previously called cytochrome a
1. The reaction of the fully reduced complex with oxygen involves ligand binding to the ferrous haem d to form an oxygenated species, followed by oxidation of two b‐type cytochromes, whose identity is unclear. Here we report kinetic studies on cytochrome b‐595 oxidation and suggest that these results, together with optical and EPR data on the oxidase complex and its reaction with oxygen, are consistent with the hypothesis that the role of cytochrome b‐595 is further reduction of the oxygen bound to cytochrome d.
cDNA cloning and expression in E. coli of a plasminogen activator inhibitor (PAI) related to a PAI produced by Hep G2 hepatoma cell
Authors: Wun Tze-Chein , Kretzmer Kuniko K.
Published: July 2002

The human hepatoma line Hep G2 produces an acid‐ and SDS‐sensitive plasminogen activator inhibitor (PAI). This protein has been previously purified and used to raise polyclonal antibodies. This antiserum has been used to isolate cDNA clones from a human placental λgtll cDNA library. The immunologically positive clones were screened for expression of recombinant proteins which inhibit urokinase activity and form an inhibitor‐enzyme complex with 125I‐urokinase. Two positives (λPAI 11.1 and λPAI 14.1) have been obtained. The cDNA insert of the longer isolate (λPAI 14.1) consists of 1962 base pairs encoding the entire mature Hep G2 PAI and a 3'‐noncoding region of 801 base pairs. The clone apparently lacks portions of 5'‐ and 3'‐untranslated sequences. The translated amino acid sequence matches the sequence obtained for the mature Hep G2 PAI and consists of 379 amino acids with a molecular mass of 42 770 Da. Interestingly, this PAI clone is quite different from the placental‐type PAI‐2 sequence as expected, but matches the sequence of the endothelial‐type PAI (PAI‐1) reported to be acid‐insensitive and SDS‐enhancible.
The Kok effect and the light‐inhibition of chlororespiration in Chlamydomonas reinhardtii
Authors: Peltier Gilles , Sarrey Frédéric
Published: July 2002

Measurements of O2 exchange have been performed as a function of light intensity in the green alga Chlamydomonas
reinhardtii by using 18O2, and mass spectrometry. The Kok effect (i.e. a decrease in the slope of net O2 exchange curve) was observed at a light intensity of about 15 μE·m−2·s−1. This effect was due to the inhibition by light of O2 uptake. In conditions where mitochondrial respiration was inhibited by antimycin A and salicyl hydroxamic acid, illumination was found to reduce O2 uptake to the same extent as in the control experiment. We conclude that the Kok effect in Chlamydomonas is not the consequence of the inhibition of mitochondrial respiration, but is due to the inhibition of chlororespiration induced by photosystem I activity.
A new crystalline form of 30 S ribosomal subunits from Thermus thermophilus
Authors: Yusupov M.M. , Tischenko S.V. , Trakhanov S.D. , Ryazantsev S.N. , Garber M.B.
Published: July 2002

A new crystalline form of 30 S ribosomal subunits from an extremely thermophilic bacterium Thermus thermophilus has been obtained. Positively stained ultrathin sections of the crystals have been analysed by electron microscopy. The crystals show X‐ray diffraction to about 12 Å resolution in a synchroton beam at 0°C.
Site‐specific enzymatic cleavage of TMV RNA directed by deoxyribo‐ and chimeric (deoxyribo‐ribo)oligonucleotides
Authors: Atabekov K.J. , Tyulkina L.G. , Karpova O.V. , Metelev V.G. , Rodionova N.P. , Shabarova Z.A. , Atabekov J.G.
Published: July 2002

The TMV RNA molecule can be cleaved at a single site by RNase H directed by chimeric oligo(deoxyribo‐ribo)nucleotide with an internucleotide pyrophosphate bond
Mammalian valyl‐tRNA synthetase forms a complex with the first elongation factor
Authors: Motorin Yu.A. , Wolfson A.D. , Orlovsky A.F. , Gladilin K.L.
Published: July 2002

The high‐molecular‐mass form of valyl‐tRNA synthetase is associated with the first elongation factor activity. It includes two polypeptides of about 50 kDa and two others of 40 and 30 kDa, identified as α, β, γ and δ subunits of eEF‐1H. The complex of valyl‐tRNA synthetase with eEF‐1H is suggested to be a novel form of the first elongation factor.
Determination of intermediates, products and cleavage site in the reaction between plasminogen activator inhibitor type‐2 and urokinases
Authors: Kiso U. , Kaudewitz H. , Henschen A. , Åstedt B. , Kruithof E.K.O. , Bachmann F.
Published: July 2002

Several specific inhibitors for plasminogen activators have been isolated from various organs and cell lines, those from human placenta and the human monocyte‐like cell line U‐937 being virtually identical. The reaction between this type of inhibitor, designated as type‐2, and high‐M
r and low‐M
r urokinase‐type plasminogen activators was followed by reversed‐phase high‐performance liquid chromatography and gel electrophoresis. The components, their stable complexes and their dissociation and cleavage products could be clearly identified in both systems. The amino acid sequence of the inhibitor at the cleavage site was determined to be ‐Met‐Thr‐Gly‐Arg↓Thr‐Gly‐His‐Gly‐. A 35‐residue carboxy‐terminal fragment was found to be released.
Expression of a human liver cDNA encoding a UDP‐glucuronosyltransferase catalysing the glucuronidation of hyodeoxycholic acid in cell culture
Authors: Fournel-Gigleux S. , Jackson M.R. , Wooster R. , Burchell B.
Published: July 2002

A cDNA encoding a human liver UDPGT (HLUG 25) transcribed and translated in vitro showed that the encoded protein was synthesized as a precursor and was cleaved and glycosylated when dog pancreatic microsomes were present during translation. The UDPGT cDNA was transiently expressed in mammalian cell culture (COS‐7 cells) resulting in the biosynthesis of a polypeptide of 52 kDa. This expressed UDPGT glycoprotein catalysed the glucuronidation of hyodeoxycholic acid forming an ether glucuronide. These results suggest that this UDPGT isoenzyme may be responsible for the glucuronidation of 6α‐hydroxy bile acids in human liver.
Intracellular targetting signals of polymeric immunoglobulin receptors are highly conserved between species
Authors: Banting George , Brake Brigitte , Braghetta Paola , Luzio J.Paul , Stanley Keith K.
Published: July 2002

A rat liver cDNA library, constructed in the plasmid expression vector pUEX, was immunoscreened using a rabbit polyclonal antiserum raised against rat liver Golgi membrane proteins. A sub‐set of isolated clones were shown to encode the rat polymeric immunoglobulin receptor (pIgR). DNA sequence analysis of these clones provided the complete coding sequence of rat pIgR. Subsequent alignment of rat, rabbit and human predicted amino acid sequences demonstrated that the greatest degree of homology between the three pIgRs lies in their cytoplasmic tails; a region previously shown to be important for correct targetting and trancytosis of rabbit pIgR [(1984) Nature 308, 37–43].
S‐100a0 protein stimulates Ca2+ ‐induced Ca2+ release from isolated sarcoplasmic reticulum vesicles
Authors: Fanò G. , Marsili V. , Angelella P. , Aisa M.C. , Giambanco I. , Donato R.
Published: July 2002

S‐100a0 protein, the αα‐isoform of the S‐100 family, stimulates Ca2+ ‐induced Ca2+ release from terminal cisternae isolated from rat skeletal muscle cells. The stimulatory effect of S‐100a0 is maximal at ∼5 μM S‐100a0 and half maximal at ∼0.1 μM S‐100a0, at 1.8 μM free Ca2+ in the presence of 5 mM Mg2+ plus 0.1 M KCl. The effect of the protein on Ca2+ ‐induced Ca2+ release is completely inhibted by the calcium release blocker, ruthenium red.
Zinc increases phorbol ester receptors in intact B‐cells, neutrophil polymorphs and platelets
Authors: Forbes I.J. , Zalewski P.D. , Hurst N.P. , Giannakis C. , Whitehouse M.W.
Published: July 2002

In the presence of pyrithione, which was used as a Zn2+ ionophore, Zn2+ (10–100 μM) increased phorbol ester binding by intact B‐CLL cells in a dose‐dependent fashion. Zn pyrithione increased 2‐fold the number of phorbol ester receptors in B‐cells (0.74 to 1.4 pmol/106 cells), neutrophil polymorphs (0.2 to 0.51 pmol/106 cells) and platelets (91 to 209 pmol/1010 cells). Fractionation of cells after treatment with Zn pyrithione showed that increased binding of PDBu occurred in the particulate fraction of cells and this was accompanied by loss of phorbol ester receptors from the cytosol. These data are compatible with a role for Zn in the subcellular distribution and activation of protein kinase C.
The efficiency of interaction of deoxyribonucleosid‐5'‐mono‐, di‐ and triphosphates with the active centre of E. coli DNA polymerase I Klenow fragment
Authors: Doronin S.V. , Nevinsky G.A. , Malygina T.O. , Podust V.N. , Khomov V.V. , Lavrik O.I.
Published: July 2002

The interaction of deoxyribonucleoside‐5'‐mono‐, di‐ and triphosphates with E. coli DNA polymerase I Klenow fragments was examined. Dissociation constants of the enzyme complex with nucleotides were determined from the data on the enzyme inactivation by adenosine 2',3'‐riboepoxide 5'‐triphosphate. The role of nucleotide bases, phosphate groups and sugar moieties in the complex formation of nucleotides with the enzyme was elucidated. The necessity of complementary interaction of nucleotides with templates for template‐controlled ‘adjusting’ of complementary dNTP to its reactive state was found. The crucial role of the interaction of dNTP γ‐phosphate with the enzyme in this process is discussed.
Gene duplication as a means for altering H+/ATP ratios during the evolution of Fo F1 ATPases and synthases
Authors: Cross Richard L. , Taiz Lincoln
Published: July 2002

In the evolution of the FoF1 family of proton‐translocating membrane complexes, two reversals in function appear to have occurred, first changing it from an ATPase to an ATP synthase and then back again to an ATPase. Here we suggest that with each change in function, the ratio of protons transported per ATP hydrolyzed or synthesized (H+/ATP) was altered in order for the complex to better adapt to its new role. We propose that this was accomplished by gene duplication with partial loss in the number of functional catalytic sites (to increase H+/ATP) or functional proton channels (to decrease H+/ATP). This method of changing the H+/ATP ratio preserved overall structural features of the complex essential to energy coupling.
PAPS‐reductase of Escherichia coli
Authors: Krone Frank A. , Westphal Goetz , Meyer Helmut E. , Schwenn Jens D.
Published: July 2002

The DNA of the gene complementing a PAPS‐reductase‐deficient strain of Escherichia coli was sequenced. The N‐terminal amino acid sequence of the purified PAPS‐reductase confirmed that cys H is the structural gene for this enzyme. The open reading frame extends 732 bases and encodes for a peptide of M
r = 27927. The gene product is functionally active when supplemented with thioredoxin and immunologically related with the wild type enzyme.
Inhibitors of the ATP/ADP antiporter suppress stimulation of mitochondrial respiration and H+ permeability by palmitate and anionic detergents
Authors: Brustovetsky N.N. , Dedukhova V.I. , Egorova M.V. , Mokhova E.N. , Skulachev V.P.
Published: July 2002

The action of ATP/ADP‐antiporter inhibitors upon the uncoupling effect of palmitate, detergents and ‘classical’ uncouplers has been studied. The uncoupling effect was estimated by stimulation of succinate oxidation and of H+ permeability of rat liver mitochondria in the presence of oligomycin. It is shown that carboxyatractylate (CAtr) and pyridoxal 5‐phosphate (PLP) suppress the uncoupling induced by palmitate and the anionic detergents SDS and cholate, but do not affect that induced by the cationic detergents CTAB, by the non‐ionic detergent Triton X‐100, as well as by the ‘classical’ uncouplers FCCP and DNP. The results are discussed in terms of a concept assuming that the ATP/ADP‐antiporter facilitates the electrophoretic export of hydrophobic anions from mitochondria.
Coupling site I and the rotenone‐sensitive ubisemiquinone in tightly coupled submitochondrial particles
Authors: Kotlyar A.B. , Sled V.D. , Burbaev D.Sh. , Moroz I.A. , Vinogradov A.D.
Published: July 2002

The rotenone‐sensitive g = 2.00 low temperature EPR signal attributed to ubisemiquinone is observed in submitochondrial particles during coupled electron transfer from NADH to oxygen and from succinate to NAD+. The signal is seen only in the presence of oligomycin added to induce the respiratory control (7–9 with NADH and 3–4 with succinate) and it disappears in the presence of uncouplers (CCCP or gramicidin D). No reduction of the iron‐sulfur center N‐2 in the presence of 20 mM succinate and cyanide is observed, thus suggesting that N‐2 is not in equilibrium with the ubiquinone pool. A hypothesis is proposed on 7Delta;smH+ generation coupled with electron transfer between iron‐sulfur center N‐2 and the ubiquinone pool.
Flufenamic acid, mefenamic acid and niflumic acid inhibit single nonselective cation channels in the rat exocrine pancreas
Authors: Gögelein H. , Dahlem D. , Englert H.C. , Lang H.J.
Published: July 2002

The non‐steroidal anti‐inflammatory drugs, flufenamic acid, mefenamic acid and niflumic acid, block Ca2+‐activated non‐selective cation channels in inside‐out patches from the basolateral membrane of rat exocrine pancreatic cells. Half‐maximal inhibition was about 10 μM for flufenamic acid and mefenamic acid, whereas niflumic acid was less potent (IC50 about 50 μM). Indomethacin, aspirin, diltiazem and ibuprofen (100μM) had not effect. It is concluded that the inhibitory effect of flufenamate, mefenamate and niflumate is dependent on the specific structure, consisting of two phenyl rings linked by an amino bridge.
A genomic clone encoding a cryptophyte phycoerythrin α‐subunit
Authors: Jenkins Jon , Hiller Roger G. , Speirs Jim , Godovac-Zimmermann Jasminka
Published: July 2002

A genomic library of Chroomonas (Cryptophyceae) DNA has been constructed in λEMBL4. Using a synthetic oligomer as a hybridization probe, a clone containing a phycoerythrin α‐subunit has been obtained and sequenced. The principal α1 and α2‐subunits of the holoprotein have been partially sequenced by sequential Edman degradation and differ from the DNA derived sequence, providing evidence for at least 3 α‐subunit genes. The nucleotide sequence of the α‐subunit gene is GC rich and encodes an N‐terminal extension which is putatively thylakoid‐lumen directing.
QA‐depletion and reconstitution of a reaction center preparation from the photosynthetic bacterium Rhodopseudomonas viridis
Authors: Liu Ben-li , Hoff Arnold J.
Published: July 2002

Isolated RC's from Rps. viridis were reversibly depleted of both UQ (QB) and MK (QA). The photochemical activity was eliminated and restored upon the depletion and reconstitution of the QA. Four methods for depleting QA from the RC's were studied and their results were compared. The best way allowed us for the first time to prepare QA‐depleted RC's from Rps. viridis that retained only 10% of primary photochemical activity, which could be restored up to 85% by addition of vitamin K1.
A homologue of dystrophin is expressed at the neuromuscular junctions of normal individuals and DMD patients, and of normal and mdx mice Immunological evidence
Authors: Pons F. , Augier N. , Léger J.O.C. , Robert A. , Tome F.M.S. , Fardeau M. , Voit T. , Nicholson L.V.B. , Mornet D. , Léger J.J.
Published: July 2002

Polyclonal and monoclonal antibodies, which recognize different regions and epitopes of the dystrophin molecule, bind to a protein of M
r 400 000 which is present in extracts of mdx muscle from regions which contain neuromuscular junctions (NMJ) and is absent from those which do not. This NMJ‐associated homologue of dystrophin has at least 2 epitopes which are different to the usual Xp21 form of dystrophin expressed along the sarcolemma of muscle fibres in normal muscles. This protein is also expressed at the NMJ of a DMD patient who lacks the first 52 exons of the Xp21 dystrophin gene and it must therefore be translated from a different gene transcript.
Inhibition of lipid peroxidation by ubiquinol in submitochondrial particles in the absence of vitamin E
Authors: Forsmark Patrik , Åberg Fredrik , Norling Birgitta , Nordenbrand Kerstin , Dallner Gustav , Ernster Lars
Published: July 2002

The relationship between the antioxidant effects of reduced coenzyme Q10 (ubiquinol, UQH2) and vitamin E (α‐tocopherol) was investigated in beef heart submitochondrial particles in which lipid peroxidation was initiated by incubation with ascorbate + ADP‐Fe3+. These effects were examined after extraction of coenzyme Q10 (UQ‐10) and vitamin E from the particles and reincorporation of the same components alone or in combination. The results show that UQHZ efficiently inhibits lipid peroxidation even when vitamin E is absent. It is concluded that UQH2 can inhibit lipid peroxidation directly, without the mediation of vitamin E.
Extensive multiplicity of the miscellaneous type of neurotoxins from the venom of the cobra Naja naja naja and structural characterization of major components
Authors: Shafqat Jawed , Siddiqi Abdur Rehman , Zaidi Zafar H. , Jörnvall Hans
Published: July 2002

A multiplicity of miscellaneous type neurotoxins were detected in the venom of the cobra Naja naja naja by use of reverse‐phase HPLC and FPLC. The primary structures of major forms were determined, giving 4 novel structures. All four contain 62–65 residues, with 10 half‐cystine residues and resemble the miscellaneous type of toxins from other Naja species. Differences within the species are extensive, exchanges occur at 27 positions, giving only 58% residue identity between all forms. However, the differences are largely limited to 3 regions corresponding to structurally important loops where two functional residues participating in receptor binding are exchanged. The four miscellaneous neurotoxins now characterized, together with the minor components of the miscellaneous type, the minimally four neurotoxins reported before, and other related toxins, indicate the existence of an extensive toxin gene multiplicity.
Respiratory chain activity in tissues from patients (MELAS) with a point mutation of the mitochondrial genome [tRNALeu(UUR)]
Authors: Obermaier-Kusser B. , Paetzke-Brunner I. , Enter C. , Müller-Höcker J. , Zierz S. , Ruitenbeek W. , Gerbitz K.-D.
Published: July 2002

A heteroplasmic point mutation (transition A to G at position 3243 in the mitochondrial tRNALeu(UUR) gene is indicative for myo‐encephalopathy with lactic acidosis and stroke‐like episodes (MELAS). Decreased respiratory chain complex activities measured in different tissues from four patients with MELAS syndrome do not correlate with the proportion of mutated mitochondrial genome.
Widespread tissue distribution, species distribution and changes in activity of Ca2+‐dependent and Ca2+‐independent nitric oxide synthases
Authors: Salter Mark , Knowles Richard G. , Moncada Salvador
Published: July 2002

The distribution of Ca2+‐dependent and Ca2+‐independent nitric oxide synthase (NOS) was studied in rabbits and in control and endotoxin‐treated rats and guinea‐pigs. There was a widespread localization of NOS which differed for the two forms of the enzyme and which showed marked differences between species. Endotoxin induced the activity of the Ca2+‐independent NOS in many tissues and also increased the activity of Ca2+‐dependent NOS in the rat ileum and caecum. These results demonstrate the differential distribution of NOSs in control and endotoxin‐treated animals and emphasize the widespread biological role of nitric oxide (NO).
Chlorophyll catabolism in Chlorella protothecoides Isolation and structure elucidation of a red bilin derivative
Authors: Engel Norbert , Jenny Titus A. , Mooser Véronique , Gossauer Albert
Published: July 2002

When grown in a medium rich in glucose but poor in nitrogen, the algae Chlorella protothecoides excrete a red pigment the structure of which has been proven to correspond to a product of oxydative ring cleavage of the chlorophyll‐α chromophore at the C4–C5 methine bridge.
Phosphorylation of cytochrome b6 by the LHC II kinase associated with the cytochrome complex
Authors: Gal Alma , Herrmann Reinhold G. , Lottspeich Friedrich , Ohad Itzhak
Published: July 2002

The cytochrome b6 polypeptide present in cytochrome b6/| preparations from spinach thylakoids is phosphorylated concomitantly with the autophosphorylation of the 64 kDa polypeptide identified as the redox‐controlled LHCII kinase. The N‐terminal sequence of the 64 kDa kinase and sequence analysis of cytochrome b6 indicate the existence of putative phosphorylation sites in both proteins.
Action of Escherichia coli and human 5′ → 3′ exonuclease functions at incised apurinic/apyrimidinic sites in DNA
Authors: Price Allan
Published: July 2002

The 5′ → 3′ exonuclease activity of E. coli DNA polymerase I and a related enzyme activity in mammalian cell nuclei. DNase IV, are unable to catalyse the excision of free deoxyribose‐phosphate from apurinic/apyrimidinic (AP) sites incised by an AP endonuclease. Instead, the sugar phosphate residue is slowly released as part of a short oligonucleotide. These products have been characterised as dimers and trimers by comparison or their retention time on reverse‐phase HPLC with reference compounds prepared by acid depurination of a dinucleotide, trinucleotide and tetranucleotide containing a 5′‐terminal dAMP residue. The similar mode of action of these enzymes at 5′‐incised AP sites provides an explanation for the minority of repair patches larger than one nucleotide observed when AP sites arc repaired by E. coli and mammalian cell extracts in vitro and strengthens the functional analogy between the two activities.
Coexistence of two calsequestrin isoforms in rabbit slow‐twitch skeletal muscle fibers
Authors: Biral Donatella , Volpe Pompeo , Damiani Ernesto , Margreth Alfredo
Published: July 2002

The cardiac and skeletal muscle isoforms of calsequestrin (CS), the low affinity, high capacity Ca2+ binding protein localized in the lumen of sarcoplasmic reticulum, are the products of two different genes (Fliegel, L., Leberer, E., Green, N.M. and MacLennan, D.H. (1982) FEBS Lett. 242, 297–300), and can be both purified from slow‐twitch skeletal muscle of the rabbit (Damiani, E., Volpe, P. and Margreth, A. (1990) J. Muscle Res. Cell Motil. 11, 522–530). Here we show that both CS isoforms coexist in slow‐twitch muscle fibers as indicated by indirect immunofluorescent staining of cryosections with affinity‐purified antibodies specific for each CS isoform.
Assignment of the redox potentials to the four haems in Desulfovibrio vulgaris cytochrome c3 by 2D‐NMR
Authors: Salgueiro Carlos A. , Turner David L. , Santos Helena , LeGall Jean , Xavier António V.
Published: July 2002

Using 2D‐NMR the four haems of Desulfovibrio vulgaris (Hildenborough) cytochromes, within the X‐ray structure were fully cross‐assigned according to their redox potential. The strategy used was based on a complete network of chemical exchange connectivities between the NMR signals obtained for all oxidation levels to the corresponding ones in the fully reduced spectrum [1992, Eur. J. Biochem., in press]. This unequivocal cross‐assignment disagrees within earlier results obtained for the similar protein from Desulfovibrio vulgaris (Miyazaki F.) [1991, FEBS Lett. 285, 149–151]
Involvement of a d‐type oxidase in the Na+‐motive respiratory chain of Escherichia coli growing under low Δ\̄gmH+ conditions
Authors: Avetisyan Armine V. , Bogachev Alexander V. , Murtasina Rakhilya A. , Skulachev Vladimir P.
Published: July 2002

An attempt has been made to find out which of the two terminal oxidases, the d‐type or the o‐type, operates as a Na+ pump in Escherichia coli grown at low Δ\̄gmH+ conditions. For this purpose, mutants lacking either d or o oxidase have been studied. It is shown that a d
−,o
+ mutant grows slowly or does not grow at all under low Δ\̄gmH+ conditions (alkaline or protonophore‐containing growth media were used). Inside‐out subcellular vesicles from the d
−,o
+ mutant cannot oxidize ascorbate and TMPD, and cannot transport Na+ when succinate is oxidize in the presence of a protonophore. The same vesicles are found to transport Na+ when NADH is oxidized as if the Na+‐motive NADH‐quinone oxidase were operative. On the other hand, a mutant lacking o oxidase (d
+,o
−) grows at low Δ\̄gmH+ conditions as fast as the maternal E. coli strain containing both d and o oxidases. Corresponding vesicles oxidize ascorbate and TMPD as well as succinate, the oxidations being coupled to the protonophore‐stimulated Na+ transport. Growth in the presence of a protonophore is found to induce a strong increase in the d oxidase level in the maternal d
+,o
+
E. coli strain. It is concluded that oxidase of the d‐type, rather than of the o‐type, operates as a Na+ pump in E. coli grown under conditions unfavorable for the H+ cycle.
Molecular basis for low temperature compartment formation by transitional endoplasmic reticulum of rat liver
Authors: Moreau Patrick , Juguelin Hélène , Cassagne Claude , Morré D.James
Published: July 2002

The molecular basis for temperature compartment formation was investigated using a cell‐free system from rat liver. The donor was from liver slices prelabeled with [3H]acetate. Unlabeled Golgi apparatus membranes were immobilized on nitrocellulose as the acceptor. When transfer was determined as a function of temperature, a transition in transfer activity was observed at low temperatures (≤ 20°C) similar to that seen in vivo. The decrease in transfer efficiency correlated with a decrease in phosphatidylethanolamine and phosphatidylserine content of the transition vesicles formed. By adding lipid mixtures enriched in these lipids to the vesicles, their ability to fuse with the cis Golgi apparatus was reconstituted. These findings provide evidence for a role for lipids in low temperature compartment formation.
An alternative mechanism for the nitrogen transfer reaction in asparagine synthetase
Authors: Richards Nigel G.J. , Schuster Sheldon M.
Published: July 2002

In the absence of crystallographic data, the mechanism of nitrogen transfer from glutamine in asparagine synthetase (AS) remains under active investigation. Surprisingly, the glutamine‐dependent AS from Escherichia coli (AsnB) appears to lack a conserved histidine residue, necessary for nitrogen transfer if the reaction proceeds by the accepted pathway in other glutamine amidotransferases, but retains ability to synthesize asparagine. We propose an alternative mechanism for nitrogen transfer in AsnB which obviates the requirement for participation of histidine in this step. Our hypothesis may also be more generally applicable to other glutamine‐dependent amidotransferases.
Cloning and expression of a cDNA for the rat k‐opioid receptor
Authors: Minami Masabumi , Toya Takashi , Katao Yoshikazu , Maekawa Keiko , Nakamura Shunya , Onogi Tatsuhiro , Kaneko Shuji , Satoh Masamichi
Published: July 2002

We cloned a cDNA for the rat K‐opioid receptor from a rat thalamus cDNA library. The deduced amino acid sequence consists of 380 residues with features shared by members of the G protein‐coupled receptor family. The specific binding of [3H]bremazocine to the membrane of COS‐7 cells transfected with the cDNA was displaced by k‐specific opioid ligands, but not by μ‐ and δ‐specific ligands. Xenopus oocytes injected with the in vitro transcribed mRNA responded to opioid ligands with the same subtype specificity. Northern blot analysis demonstrated that k‐opioid receptor mRNA is expressed in a regionally specific manner in rat brain.
Autoimmune Addison's disease
Authors: Wedlock N. , Asawa T. , Baumann-Antczak A. , Smith B.Rees , Furmaniak J.
Published: July 2002

Human steroid 21‐hydroxylase (21‐OH) expressed in an in vitro translation system was found to react specifically with adrenal autoantibodies from patients with Addison's disease. The epitopes on 21‐OH which reacted with autoantibodies were studied by incorporating a series of terminal and internal deletions into the 21‐OH gene and analysing the expressed proteins by Western blotting. N‐Terminal deletions up to amino acid 280 had no effect on autoantibody binding whereas a series of C‐terminal deletions and truncations (amino acids 281–494) showed marked effects. Our results indicate that a central segment (281–379) and a C‐terminal segment (380–494) of 21‐OH interact to form at least one major autoantibody binding site.
Flash‐induced membrane potential generation by cytochrome c oxidase
Authors: Zaslavsky Dmitry , Kaulen Andrey D. , Smirnova Irma A. , Vygodina Tatiana , Konstantinov Alexander A.
Published: July 2002

Flash‐induced single‐electron reduction of cytochrome c oxidase. Compound F (oxoferryl state) by RuII(2,2'‐bipyridyl)2+
3 [Nilsson (1992) Proc. Natl. Acad. Sci. USA 89, 6497‐6501] gives rise to three phases of membrane potential generation in proteoliposomes with τ values and contributions of ca. 45 μs (20%), 1 ms (20%) and 5 ms (60%). The rapid phase is not sensitive to the binuclear centre ligands, such as cyanide or peroxide, and is assigned to vectorial electron transfer from CuA to heme a. The two slow phases kinetically match reoxidation of heme a, require added H2O2 or methyl peroxide for full development, and are completely inhibited by cyanide; evidently, they are associated with the reduction of Compound F to the Ox state by heme a. The charge transfer steps associated with the F to Ox conversion are likely to comprise (i) electrogenic uptake of a ‘chemical’ proton from the N phase required for protonation of the reduced oxygen atom and (ii) electrogenic H+ pumping across the membrane linked to the F to Ox transition. Assuming heme a ‘electrical location’ in the middle of the dielectric barrier, the ratio of the rapid to slow electrogenic phase amplitudes indicates that the F to Ox transition is linked to transmembrane translocation of 1.5 charges (protons) in addition to an electrogenic uptake of one ‘chemical’ proton required to form Fe3+‐OH− from Fe4+ = O2−. The shortfall in the number of pumped protons and the biphasic kinetics of the millisecond part of the electric response matching biphasic reoxidation of heme a may indicate the presence of 2 forms of Compound F, reduction of only one of which being linked to full proton pumping.