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1.
Stimulation by interferon of induction of differentiation of human promyelocytic leukemia cells 总被引:3,自引:0,他引:3
F1-ATPase was isolated from yeast . The constituent subunits 1 and 2 were purified by gel permeation chromatography, and their amino acid compositions determined. Both subunits have a similar composition except for cystine, methionine, leucine, histidine, and tryptophan. When F1 is treated for three hours with 5′-p-[3H]fluorosulfonylbenzoyl adenosine in dimethylsulfoxide, 90% of the activity is lost. Disc gel electrophoresis of the modified complex showed that over 90% of the label was associated with subunit 2. A labelled peptide from a digest of subunit 2 was isolated and sequenced. It had the following amino acid sequence: His-Try1-Asp-Val-Ala-Ser-Lys-Val-Gln-Glu, whereby Tyr1 is the modified amino acid residue. This sequence shows homology to other sequences obtained from maize, beef heart, and F1-ATPases. 相似文献
2.
拟南芥色氨酸与吲哚乙酸生物合成的研究进展 总被引:1,自引:0,他引:1
拟南芥色氨酸生物合成途径的研究已逐渐成为植物分子生物学家了解植物基因结构和表达调控最主要的模式系统之一。到目前为止,编码拟南芥色氨酸合成途径的七种酶蛋白的基因已经全部被克隆,并进行了不同程度的分子生物学研究。长期以来,色氨酸一直被认为是植物生长素吲哚乙酸(IAA)生物合成(从头合成)的前体物,但近年来人们发现生长素合成的非色氨酸途径可能是其在植物中生物合成的主要途径。植物在不同的发育阶段可能采用不同的方式合成IAA。 相似文献
3.
A method has been developed to recover pure ribosomal proteins from two-dimensional polyacrylamide electrophoresis slabs. Proteins and Coomassie blue were extracted from the gels and separated by passing them through a Sephadex G-25 column. All the steps were performed in the presence of 66% () acetic acid. The technique has been applied to Escherichia coll ribosomal proteins labeled with 125I. 相似文献
4.
Chester Meyers Akira Arimura Ariel Gordin R. Fernandez-Durango David H. Coy Andrew V. Schally Jacques Drouin Louise Ferland Michele Beaulieu Fernand Labrie 《Biochemical and biophysical research communications》1977,74(2):630-636
Three analogs of somatostatin, [-Cys14] -, [Ala2, -Cys14] - and [-Trp8, -Cys14] - somatostatin, were synthesized by the solid phase method, characterized by several means, and tested for their effects on the release of insulin, glucagon, and growth hormone. The peptides sharply suppressed the release of growth hormone and glucagon , but had less effect on insulin secretion . These analogs, particularly [-Trp8, -Cys14] - somatostatin, could possibly be useful for the treatment of diabetes mellitus. 相似文献
5.
Bovine pancreatic ribonuclease has been modified by exposure to acidic conditions, addition of indole propionic acid and crosslinking with glutaraldehyde. The ‘acid-esterase’ generated was purified up to 100-fold by ammonium sulphate fractionation and gel filtration on Biogel P-30. The partially purified acid-esterase hydrolysed tryptophan ethyl ester (TrEE) and ethyl ester (BAEE) effectively at pH 6.0–6.3, but it had very little activity towards glycine ethyl ester and lysine ethyl ester. Hydrolysis of TrEE was competitively inhibited by tryptophan. The acid-esterase exhibited amidase activity towards benzoyl-l-arginine p-nitroanilide. 相似文献
6.
E Gallori M Bazzicalupo B Parisi G Pedaggi M Polsinelli 《Biochemical and biophysical research communications》1978,85(4):1518-1525
A spontaneous mutant of resistant to (L)-azetidin-2-carboxylic acid, a structural analogue of (L)-proline, has been isolated and characterized. Data have been obtained which indicate that binding of [14C]-proline to tRNAs from the resistant strain is reduced only in part by (L)-azetidin-2-carboxylic acid, while a complete inhibition of binding occurs using tRNAs from parental strain. The mutation conferring resistance to the analogue and a mutation for proline auxotrophy have been mapped. 相似文献
7.
Y.S. Chauhan V.S. Rathore G.K. Garg Aruna Bhargava 《Biochemical and biophysical research communications》1978,83(4):1237-1245
An enzyme activity which brings about a rapid indole disappearance has been detected in cell free extracts of maize ( L.) leaves. The indole utilization by this enzyme system is not dependent on L-serine and pyridoxal phosphate. It does not result in incorporation of (5-3H) indole or (1-14C) serine into tryptophan. There was no net tryptophan synthesis concomittant with indole disappearance. The enzyme activity is strongly inhibited by dithionite and diethyl-dithiocarbamate. The inhibition by the latter could be specifically removed by Cu2+. The activity of dialyzed enzyme could be restored by addition of Cu2+ and FAD. The products of indole oxidation were characterized as anthranilic acid and anthranil (2,1-benzisooxazole). The activity of the indole oxidizing system was 2 to 3 times higher in normal maize varieties (Ganga-2 and Ganga-5) than in Opaque-2. 相似文献
8.
9.
E L Kline V Bankaitis C S Brown D Montefiori 《Biochemical and biophysical research communications》1979,87(2):566-574
The ability of imidazole acetic acid (IA) to substitute for cAMP was demonstrated by use of a series of strains carrying a lesion in the structural gene. The substitution of IA for cAMP was specific for the L-arabinose operon in that this compound was ineffective in substituting for cAMP in the lactose or maltose catabolic systems. The cAMP receptor protein (CRP) and the gene product were necessary for the IA mediated induction of the L-arabinose system. 相似文献
10.
A sensitive and specific assay method for cysteine sulfinic acid (CSA) and cysteic acid (CA) using high-performance liquid chromatography has been developed. The method includes post-column derivatization of various amino acids with o-phthalaldehyde in the presence of 2-mercaptoethanol. The column packed with cation-exchange resin (, Shimadzu Sci entific instruments, Inc., Kyoto, Japan) was used for obtaining general separation of amino acids except CSA and CA, while the separation of CSA and CA was achieved using a strong-base anion exchange (, Shimadzu Scientific Instruments) column. The fluorescence peak area for CSA was linear between 20 pmol and 5 nmol, whereas that for CA was 10 pmol to 5 nmol. The regional distribution of CSA, CA, and other amino acids in the rat brain was studied using this new assay method. 相似文献
11.
T. Isobe N. Ishioka T. Kadoya T. Okuyama 《Biochemical and biophysical research communications》1982,105(3):997-1004
An acidic protein, designated as micro glutamic acid-rich protein, was purified to homogeneity from bovine brain extract, and was characterized in its physicochemical properties. The protein had an isoelectric point of 3.9, a molecular weight of 10,000, and was composed of very limited amino acid constituents; , Thr, Ser, , Pro, Gly, Ala and Lys, with a relative abundance of glutamic acid/glutamine which accounted for 51 % of the total amino acid composition. The yield of the protein was 750 μg/kg of wet brain tissue. The amino-terminal sequence analysis suggested that the protein arose through proteolysis of the 58,000-dalton precursor protein, that had been reported in a previous paper [Ishioka , (1980) Biochim. Biophys. Acta, 625, 281–290]. 相似文献
12.
S Nasu F D Wicks S Sakakibara R K Gholson 《Biochemical and biophysical research communications》1978,84(4):928-935
Two proteins (A and B) from are required for the synthesis of the NAD precursor quinolinate from aspartate and dihydroxyacetone phosphate. Mammalian liver contains a FAD linked protein which replaces B protein for quinolinate synthesis. D-aspartic acid but not L-aspartic acid is a substrate for quinolinic acid synthesis in a system composed of the B protein replacing activity of mammalian liver and A protein. In contrast the B protein- A protein quinolinate synthetase system requires L-aspartic acid as substrate. The previous report that L-aspartate was a substrate in the liver- system was due to contamination of commercially available [14C]L-aspartate with [14C]D-aspartate. These and other observations suggest that liver B protein is D-aspartate oxidase and B protein is L-aspartate oxidase. 相似文献
13.
Activity of a penicillin-insensitive -endopeptidase that splits the -alanyl-meso-2,6-diaminopimelyl linkage in peptidoglycan was demonstrated in a sonic extract of . The protein with this activity was partially purified. The activity was inhibited by 3 μg per ml of deoxyribonucleic acid, suggesting that this cell wall hydrolytic enzyme is regulated by deoxyribonucleic acid or its fragments. 相似文献
14.
研究土壤食细菌线虫与细菌的相互作用及其生态功能是土壤生态学的核心内容之一。食细菌线虫取食细菌可以促进土壤中氮素的矿化,提高氮素养分的供给,改善土壤的营养条件,从而促进植物的生长发育。土壤食细菌线虫促进植物根系生长的"养分作用机制"已得到确认,而"激素作用机制"还存在争议。从供试土壤中筛选获得一株高效产IAA细菌和两种不同cp值的食细菌线虫,通过设置简化的悉生培养系统,对这两种土著食细菌线虫与土著产IAA细菌之间的相互作用,及其对土壤中IAA含量变化的影响进行研究。结果表明:两种食细菌线虫的取食均能促进细菌数量和活性的增强,食细菌线虫与产IAA细菌相互作用也能显著增加土壤中IAA的含量;这些促进作用受到接种食细菌线虫的种类以及培养时间的影响:在培养第10天和第20天时,接种cp值为1的中杆属食细菌线虫显著增加了产IAA细菌的数量;在培养第10天和第30天时,相比较接种cp值为2的头叶属食细菌线虫,接种中杆属食细菌线虫显著提高了土壤中IAA的含量。 相似文献
15.
Peter V. Hauschka A.H. Redd 《Biochemical and biophysical research communications》1980,92(3):1037-1041
γ-Carboxyglutamic acid (Gla) is a constituent of the non-collagenous bone protein osteocalcin. The appearance of γ-carboxyglutamic acid during differentiation and development of endochondral bone has been correlated with the onset of mineralization. Discrete stages of endochondral bone development were studied by subcutaneous implantation of demineralized rat diaphyseal bone matrix. Residual Gla in acid-demineralized bone matrix was lost rapidly on implantation. Gla levels were basal during mesenchymal cell proliferation (day 3) and chondrogenesis (days 5–7). Gla and calcium levels began to increase during cartilage mineralization (day 9) and continuously increased after day 10 concomitant with bone differentiation. 相似文献
16.
J A Villarreal W Vale M Brown M Butcher P Brazeau C Rivier R Burgus 《Biochemical and biophysical research communications》1976,70(2):551-558
A protein has been isolated from ovine hypothalamus on the basis of its ability to stimulate release of growth hormone by cultures of dispersed pituitary cells. This protein has been identified as being myelin basic protein. With no similar biological activity , myelin basic protein is thus to be recognized as a potentially interfering substance in any search for the physiological growth hormone releasing factor using assay systems. 相似文献
17.
Peter R. Allegrini Guus van Scharrenburg Gerard H. De Haas Joachim Seelig 《生物化学与生物物理学报:生物膜》1983,731(3):448-455
1-Palmitoyllysophosphatidylcholine has been mixed in equimolar amounts with specifically deuterated palmitic acid and the structural properties of the lipid/water phase have been studied by 2H- and 31P-nuclear magnetic resonance. The order profile of the free palmitic acid is very similar to that of the parent compound at temperatures above the gel-to-liquid crystal phase transition. The bending of the chain which is typical for diacyl lipids is not observed for the free palmitic acid. The mixture of lysolipid and palmitic acid exhibits well-defined quadrupole splittings even at temperatures below the gel-to-liquid crystal phase transition. Hence it is possible for the first time to establish an order profile in the gel-state of the lipid bilayer phase. Between carbon atoms 5 to 12 the palmitic acid chain is found to assume the extended all-trans conformation with a very small contribution from gauche defects. Towards the methyl terminal a distinct increase in the gauche probability can be noted. The motion of the phosphocholine headgroup was also studied by 2H- and 31P-NMR using selectively deuterated 1-palmitoyllysophosphatidylcholine. The headgroup has a considerably larger motional freedom in the mixture of lysolipid and palmitic acid than in . In addition, the average headgroup conformations are also different in the two systems. 相似文献
18.
Acetobacter pasteurianus strains IFO3283, SKU1108, and MSU10 were grown under acetic acid fermentation conditions, and their growth behavior was examined together with their capacity for acetic acid resistance and pellicle formation. In the fermentation process, the cells became aggregated and covered by amorphous materials in the late-log and stationary phases, but dispersed again in the second growth phase (due to overoxidation). The morphological change in the cells was accompanied by changes in sugar contents, which might be related to pellicle polysaccharide formation. To determine the relationship between pellicle formation and acetic acid resistance, a pellicle-forming R strain and a non-forming S strain were isolated, and their fermentation ability and acetic acid diffusion activity were compared. The results suggest that pellicle formation is directly related to acetic acid resistance ability, and thus is important to acetic acid fermentation in these A. pasteurianus strains. 相似文献
19.
The quantity of organic acids ( lactic acid, acetic acid, propionic acid and butyric acid ) in the content of the gastrointestinal tract of germ-free and conventional rats and the effects of the organic acid on the motility of the gastrointestinal tract of rats were investigated.Organic acids were detected only in the gastrointestinal contents of conventional rats but not in those of germ-free rats.Lactic acid detected in the stomach of rats stimulated the motility of both small and large bowel while acetic acid, propionic acid and butyric acid found in the cecum stimulated the motility of the large bowel but not of small bowel. 相似文献
20.
Methionine had been observed to interact with two principal transport systems for amino acids in mammalian cells, the A and L systems. The present study of methionine transport and of exchange processes through system A arose in the course of a study to define the specificity of a transinhibition effect caused by cysteine.Methionine uptake through two transport systems in the S37 cell was confirmed by the occurrence of a biphasic double-reciprocal plot for labeled methionine uptake. Preloading cells with methionine stimulated labeled histidine uptake through both systems A and L. Efflux of labeled methionine from cells was stimulated by histidine in a biphasic manner, so that both systems A and L can be used for exchange when methionine is the intracellular amino acid. Aminocycloheptanecarboxylic acid elicited exchange efflux of labeled methionine only through system L. α-Aminoisobutyric acid and both stimulated efflux of labeled from S37 cells. These findings are interpreted a showing that transport system A is capable of functioning as an exchange system depending upon the identity of intracellular and extracellular substrates available. 相似文献