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《Journal of enzyme inhibition and medicinal chemistry》2013,28(2):97-103
AbstractMore than 30 phosphonic and phosphinic acid analogues of aspartic and glutamic acids were synthesized in order to probe how the structural differences of these molecules were reflected in their ability to inhibit cytosolic (LAP) and microsomal (APM) aminopeptidases. Although most of the compounds studied were found to exert only a modest inhibitory effect, the studies provide some information on the structural requirements of the binding subsites and catalytic centers of both enzymes. 相似文献
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Glutamic acid producing bacteria accumulated a large amount of valine in the presence of the excess biotin, when sodium acrylate monomer (Na-AM) was added at the earlier phase of culture. Brevibacterium roseum ATCC 13825, particularly, accumulated the large amount of valine among bacteria tested and the conditions of valine accumulation by this strain were investigated.The most effective addition time of Na-AM was at the earlier phase of logarithmic phase. The optimal concentration of Na-AM for the accumulation of valine was 1.0 per cent (v/v). Most effective nitrogen sources were the combination of 1.0 per cent urea and 0.2 per cent ammonium sulphate. The additions of Mn2+ and Fe2+ increased valine accumulation. By the excess concentration of biotin for growth, 20 μg/liter or more, did not affected valine accumulation, while the presence of the suboptimal condition of biotin for growth was not good for the formation of valine even in the presence of Na-AM. The accumulation of valine reached 9.0 mg/ml from 75.0 mg/ml of glucose in the presence of 50 μg/liter of biotin and 1.0 per cent (v/v) of Na-AM.This strain possessed considerable activity of valine formation regardless of the addition of Na-AM and promoted the accumulation of valine by the addition of Na-AM. 相似文献
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Reversal by Citrate of the Iodoacetate and Fluoride Inhibition of Glutamic Acid Production by Corynebacterium glutamicum 总被引:1,自引:1,他引:0 下载免费PDF全文
Citrate reversal of iodoacetate inhibition of glutamate synthesis is nonmetabolic. Reversal of fluoride inhibition is metabolic, occurring only at low Mg concentrations. 相似文献
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Glutamic Acid Decarboxylation in Chlorella 总被引:3,自引:2,他引:1
The decarboxylation of endogenous free glutamic acid by Chlorella pyrenoidosa, Marburg strain, was induced by a variety of metabolic poisons, by anaerobic conditions, and by freezing and thawing the cells. The rate of decarboxylation was proportional to the concentration of inhibitor present. Possible mechanisms which relate the effects of the various conditions on glutamate decarboxylation and oxygen consumption by Chlorella are discussed. 相似文献
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Ethionine-induced inhibition of elongation of Avena coleoptile segments has been measured in water and in indol-3yl-acetic acid. In the presence of 10 mM L-ethionine the inhibition amounts to about 70 %. It has been shown previously that the addition of adenosine triphosphate effectively counteracts this inhibition; optimal ATP concentrations are between 0.25 and 0.5 mM. Adenine, adenine sulfate, adenosine, guanine, S-adenosylmethionine, and glutamic acid have now been shown to act similarly to ATP in reversing the ethionine-induced inhibition of elongation. 相似文献
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Inhibition of Deoxyribonucleic Acid Synthesis and Bud Formation by Nalidixic Acid in Hyphomicrobium neptunium 总被引:6,自引:5,他引:1
The relationship between chromosome replication and morphogenesis in the budding bacterium Hyphomicrobium neptunium has been investigated. Nalidixic acid was found to completely inhibit deoxyribonucleic acid synthesis, but not ribonucleic acid synthesis. The antibiotic was bacteriostatic to the organism for the initial 5 h of exposure; thereafter it was bacteriocidal. Observation of inhibited cultures revealed cells that had produced abnormally long stalks, but no buds. These results indicate that bud formation is coupled to chromosome replication in H. neptunium. They do not exclude the possibilities that cross wall formation and bud separation may also be coupled to chromosome replication. 相似文献
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Suppression of Glutamic Acid Codons by Mutant Glycine Transfer Ribonucleic Acid 总被引:1,自引:1,他引:1 下载免费PDF全文
In previous mutational studies with mutant trpA46 (Gly [GGA] --> Glu [GAA] at position 211 of the tryptophan synthetase alpha chain) of Escherichia coli, no missense suppressors were detected. Such suppressors have now been obtained by single mutations in gly Vins, the structural gene for a GGA/G-reading, mutationally altered form of gly V transfer ribonucleic acid (tRNA) (tRNA(Gly) which reads GGU/C). A trpA46 strain containing the gly Vins alteration was mutagenized with hydroxylamine, and suppressor mutations were detected in the prototrophs obtained. Eighteen independent suppressors were examined and shown to have alterations which map in the gly V region. Chromatography of the glycyl-tRNAs of one suppressed mutant on a benzoylated diethylaminoethyl-cellulose column revealed an alteration in the tRNA(ins) (Gly) peak. The trpA46 suppressor mutation thus appears to involve a change of tRNA(ins) (Gly) from a GGA/G (Gly) reader to a GAA (Glu) reader. Since this suppressor presumably retains the "wobble" pairing of gly Vins tRNA, it was used to select the conversion of GAU (Asp211) to GAG (Glu211) in the alpha chain. supD (serine-inserting amber suppressor) was then used to obtain the conversion of GAG (Glu211) to UAG211. Missense revertants of trpA (UAG211) are being isolated as a means of introducing new codons which can be used in the selection of additional missense suppressors. 相似文献
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利用噬菌体的宿主专一性,对收集的国内用于生产的谷氨酸生产菌进行鉴别,发现一株7338菌株对T6—13噬菌体敏感,而对7338的噬菌体不敏感。根据上述事实,工厂中为防止噬菌体侵袭,轮换使用不同菌株时,提出要了解菌株对不同噬菌体的敏感性,以免感染造成巨大经济损失。 相似文献
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心跳呼吸骤停及心肺脑复苏(CPCR)的过程均导致机体发生缺血/再灌注损伤(I瓜)等复杂的病理生理变化.脑的缺血再灌注损伤是一个快速的级联反应,包括能量代谢障碍、氧自由基的生成增多、兴奋性氨基酸释放增加、炎性细胞因子释放增加等.这些环节紧密连接,互为因果,形成恶性循环,最终导致神经元的凋亡或坏死.谷氨酸是大脑中一种关键的兴奋性神经递质,它的过多释放在神经元损伤发展过程中起着重要作用.随着细胞外高浓度谷氨酸的结合,N-甲基-D-天冬氨酸受体(NMDAR)开放,大量Ca2+内流,导致细胞内钙超载,是引起脑损伤的共同通路.本文就神经兴奋毒性的研究进行综述. 相似文献
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J. A. MIERNYK 《Physiologia plantarum》1979,45(1):63-66
Imbibing ‘Grand Rapids’ lettuce (Lactuca saliva L.) seeds take up 14C-kinetin, and metabolize this cytokinin to the 5′-nucleotide. The identity of the labeled nucleotide in seed extracts was verified by Sephadex LH-20 column chromatography, paper and thin layer chromatography, and high voltage paper electrophoresis. Incubations with kinetin in the presence of abscisic acid lead to an apparent specific inhibition of kinetin nucleotide formation. ABA has no effect on kinetin uptake, and does not inhibit kinetin nucleotide synthesis in vitro by a cell-free preparation from lettuce seeds. Additionally, ABA does not inhibit adenylate synthesis from exogenously supplied adenine. These results represent a specific cytokinin-ABA interaction, which might play a significant role in the hormonal regulation of lettuce seed germination. 相似文献
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Tetrodotoxin Interference of CNS Excitation by Glutamic Acid 总被引:2,自引:0,他引:2
TETRODOTOXIN (TTX), the powerful neurotoxin of the puffer fish, blocks electrical excitation of many neuronal and muscle membranes1. This neurotoxin selectively blocks the sodium conductance increase, leaving the delayed potassium conductance change unaltered2–6. 相似文献
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Tateki Hayashi Mitsuo Namiki Keiichi Tsuji 《Bioscience, biotechnology, and biochemistry》2013,77(9):1955-1960
During the formation of radical A (2) and its precursor (tris(2-deoxy-2-L-ascorbyl)amine, 1) by the reaction of dehydroascorbic acid (DHA) with amino acid, ascorbic acid (AsA) and the reduced red pigment (3) were newly identified, in addition to scorbamic acid (SCA) and the red pigment (4), as intermediate products. The addition of AsA to the DHA-amino acid reaction, as well as to the DHA-SCA reaction, greatly increased the formation of 3 and 1. The reaction of AsA with 4 gave rapidly 3, followed by the gradual production of 1. From these results, a reaction pathway is proposed that 3 formed by the reduction of 4 with AsA is a key intermediate and its condensation with DHA followed by reduction with AsA might produce 2 and 1. 相似文献
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Masanaru Misawa Takashi Nara Kiyoshi Udagawa Shigeo Abe Shukuo Kinoshita 《Bioscience, biotechnology, and biochemistry》2013,77(10):690-699
It was found that a guanine and adenine-requiring mutant of Micrococcus glutamicus accumulated the ultraviolet-absorbing substance in the culture fluid. A KY9978 strain, which accumulated the largest amount of the substance, we selected from the guanine auxotrophs derived from the guanineadenine doubleless mutant. The substance was isolated in a crystalline form from the culture fluid by the use of ion exchange resins, Diaion SA 21A and SK No. 1, and identified chemically and enzymatically as 5′-xanthylic acid, an intermediate from 5′-inosinic acid to 5′-guanylic acid on the purine nucleotide biosynthesis. 相似文献