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1.
J. Challice 《Biologia Plantarum》1984,26(6):405-409
A number of amino acids have been tested for their ability to inhibit the cytokinininduced synthesis of betacyanin inAmaranthus caudatus cotyledons. Under the conditions employed there was not any serious inhibition of pigment synthesis at amino acid concentrations belowca. 20 μg ml-1. Amino acids such as methionine, γ-aminobutyric acid and leucine did not give rise to serious inhibition belowca. 200 μg ml-1. At amino acid concentrations ofca. 2000 μg ml-1, inhibitions of pigment synthesis was in all instances complete. 相似文献
2.
The aminoglycoside antibiotic butirosin (1) has been chemically modified in its amino acid side-chain. The (S)-()-4-amino-2-hydroxybutyryl side-chain was removed by alkaline hydrolysis of the tetrakis(5,5-dimethyl-3-oxo-1-cyclohexen-1-yl) derivative. The resulting deacylated, trisubstituted derivative 3 was reacylated with a wide variety of mono and polyfunctional amino acids. The cyclohexenyl protecting groups were then removed by chlorine gas and the new analogs isolated chromatographically. Structure-activity relationships were determined with five microorganisms, including Pseudomonas aeruginosa. The specific side-chain structures that exhibited maximum potency against Pseudomonas are identified.Butirosin1, a new aminoglycoside antibiotic complex produced by mucoid strains of Bacillus circulans NRRL B-3312 and B-3313, is the first example of the aminocyclitol class of compounds to contain an amino acid in its chemical structure. Complete structural assignments for butirosin A and B have been described2 and are shown in formula 1. The amino acid, which is connected by an amide linkage to N1 of the deoxystreptamine moiety, was found to be the unique (S)-()-4-amino-2-hydroxybutyric acid2. The butirosins have marked activity against Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa, both in vitro and in vivo, as well as low toxicity in mammalian species3,4. They were therefore likely candidates for structural-modification studies. 相似文献
3.
Metabolism of Proline, Glutamate, and Ornithine in Proline Mutant Root Tips of Zea mays (L.) 总被引:2,自引:1,他引:1
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In excised pro1-1 mutant and corresponding normal type roots of Zea mays L. the uptake and interconversion of [14C]proline, [14C]glutamic acid, [14C]glutamine, and [14C]ornithine and their utilization for protein synthesis was measured with the intention of finding an explanation for the proline requirement of the mutant. Uptake of these four amino acids, with the exception of proline, was the same in mutant and normal roots, but utilization differed. Higher than normal utilization rates for proline and glutamic acid were noted in mutant roots leading to increased CO2 production, free amino acid interconversion, and protein synthesis. Proline was synthesized from either glutamic acid (or glutamine) or ornithine in both mutant and normal roots; it did not accumulate but rather was used for protein synthesis. Ornithine was not a good precursor for proline in either system, but was preferentially converted to arginine and glutamine, particularly in mutant roots. The pro1-1 mutant was thus not deficient in its ability to make proline. Based on these findings, and on the fact that ornithine, arginine, glutamic acid and aspartic acid are elevated as free amino acids in mutant roots, it is suggested that in the pro1-1 mutant proline catabolism prevails over proline synthesis. 相似文献
4.
T. A. Gudasheva V. P. Lezina E. P. Kir’yanova O. A. Deeva L. G. Kolik S. B. Seredenin 《Russian Journal of Bioorganic Chemistry》2013,39(3):259-267
The biologically active conformation of N-(6-phenylhexanoyl)glycyl-tryptophan amide (GB-115), a highly active cholecystokinin-4 retro dipeptide analogue with the anxiolytic activity, has been studied using the conformational analysis by 1H NMR spectroscopy in solution and the method of sterically restricted analogues. A study of the relationship between the preferable conformation in solution and the anxiolytic activity in the series of GB-115 derivatives showed that the biologically active conformation of this compound is the β-turn. Based on the data on the nuclear Overhauser effect 1H NMR spectroscopy, this structure was identified as the β-turn of type II. Subsequent synthesis and study of the pharmacological activity of novel sterically restricted analogues of dipeptide GB-115: (2S)-2-{(3R)-3-[(6-phenylhexanoyl)amino]-2-oxopyrrolidine-1-yl}-3-(1H-indole-3-yl)propionic acid ethyl ester, N-(6-phenylhexanoyl)glycyl-N α-methyltryptophan ethyl ester, (2S)-2-[(10,11-dihydro-5H-dibenzo[b, f]azepin-5-ylcarbonyl)amino]-3-(1H-indole-3-yl)propionic acid methyl ester, and (2S)-2-[({3-[(ethoxycarbonyl)amino]-10,11-dihydro-5H-dibenzo[b, f]azepin-5-yl}carbonyl)amino]-3-(1H-indole-3-yl)propionic acid methyl ester confirmed that the β-turn of type II is the active conformation of GB-115. 相似文献
5.
Chlorsulfuron, an inhibitor of acetolactate synthase (EC 4.1.3.18) (TB Ray 1984 Plant Physiol 75: 827-831), markedly inhibited the growth of Lemna minor at concentrations of 10−8 molar and above, but had no inhibitory effects on growth at 10−9 molar. At growth inhibitory concentrations, chlorsulfuron caused a pronounced increase in total free amino acid levels within 24 hours. Valine, leucine, and isoleucine, however, became smaller percentages of the total free amino acid pool as the concentration of chlorsulfuron was increased. At concentrations of chlorsulfuron of 10−8 molar and above, a new amino acid was accumulated in the free pool. This amino acid was identified as α-amino-n-butyrate by chemical ionization and electron impact gas chromatography-mass spectrometry. The amount of α-amino-n-butyrate increased from undetectable levels in untreated plants, to as high as 840 nanomoles per gram fresh weight (2.44% of the total free pool) in plants treated with 10−4 molar chlorsulfuron for 24 hours. The accumulation of this amino acid was completely inhibited by methionine sulfoximine. Chlorsulfuron did not inhibit the methionine sulfoximine induced accumulations of valine, leucine, and isoleucine, supporting the idea that the accumulation of the branched-chain amino acids in methionine sulfoximine treated plants is the result of protein turnover rather than enhanced synthesis. Protein turnover may be primarily responsible for the failure to achieve complete depletion of valine, leucine, and isoleucine even at concentrations of chlorsulfuron some 104 times greater than that required to inhibit growth. Tracer studies with 15N demonstrate that chlorsulfuron inhibits the incorporation of 15N into valine, leucine, and isoleucine. The α-amino-n-butyrate accumulated in the presence of chlorsulfuron and [15N]H4+ was heavily labeled with 15N at early time points and appeared to be derived by transamination from a rapidly labeled amino acid such as glutamate or alanine. We propose that chlorsulfuron inhibition of acetolactate synthase may lead to accumulation of 2-oxobutyrate in the isoleucine branch of the pathway, and transamination of 2-oxobutyrate to α-amino-n-butyrate by a constitutive transaminase utilizing either glutamate or alanine as α-amino-N donors. 相似文献
6.
Shin-Ichi Hatanaka Yoko Murooka Koshi Saito Yumiko Shida Yoshito Takeuchi 《Phytochemistry》1982,21(2):453-454
A new amino acid, E-2(S)-amino-3-methyl-3-pentenoic acid was isolated from Coniogramme intermedia. The structure was elucidated by elementary analysis, optical rotation, catalytic hydrogenation, 1H and 13C NMR spectra. 相似文献
7.
《Enzyme and microbial technology》1987,9(11):663-667
This paper describes a system for continuous synthesis of 15N-labeled l-alanine from lactic acid, 15NH4Cl and NADH, which uses immobilized alanine dehydrogenase and soluble lactate dehydrogenase as enzyme sources. Lactic acid acts both as hydrogen donor for the regeneration of NADH and as pyruvate source, thus providing the carbon skeleton of l-alanine. Citrobacter freundi grown on synthetic media containing 17 unlabeled amino acids and l-(15N)alanine as nitrogen source, incorporated 66% of 15N into alanine found in bacterial proteins. When 15N-labeled glutamic acid, aspartic acid or glycocol were added to the synthetic growth media, their 15N was “diluted” among different amino acids of bacterial proteins. Isotope enrichment of l-(15N)lysine found in newly synthesized proteins of C. freundi was practically unchanged as compared to the isotope content of free amino acid in the growth medium. 相似文献
8.
Sang-Mo Kang Raheem Shahzad Saqib Bilal Abdul Latif Khan Young-Hyun You Won-Hee Lee Hee-La Ryu Ko-Eun Lee In-Jung Lee 《Journal of microbiology (Seoul, Korea)》2017,55(12):955-965
Brassica rapa (Chinese cabbage) is an essential component of traditional Korean food. However, the crop is often subject to zinc (Zn+) toxicity from contaminated irrigation water, which, as a result, compromises plant growth and production, as well as the health of human consumers. The present study investigated the bioaccumulation of Zn+ by Burkholderia cepacia CS2-1 and its effect on the heavy metal tolerance of Chinese cabbage. Strain CS2-1 was identified and characterized on the basis of 16S rRNA sequences and phylogenetic analysis. The strain actively produced indole-3-acetic acid (3.08 ± 0.21 μg/ml) and was also able to produce siderophore, solubilize minerals, and tolerate various concentrations of Zn+. The heavy metal tolerance of B. rapa plants was enhanced by CS2-1 inoculation, as indicated by growth attributes, Zn+ uptake, amino acid synthesis, antioxidant levels, and endogenous hormone (ABA and SA) synthesis. Without inoculation, the application of Zn+ negatively affected the growth and physiology of B. rapa plants. However, CS2-1 inoculation improved plant growth, lowered Zn+ uptake, altered both amino acid regulation and levels of flavonoids and phenolics, and significantly decreased levels of superoxide dismutase, endogenous abscisic acid, and salicylic acid. These findings indicate that B. cepacia CS2-1 is suitable for bioremediation against Zn+-induced oxidative stress. 相似文献
9.
The gene encoding the extracellular neutral metalloprotease ShpI from Staphylococcus hyicus subsp. hyicus was cloned. DNA sequencing revealed an ORF of 1317 nucleotides encoding a 438 amino acid protein with Mr of 49698. When the cloned gene was expressed in Staphylococcus carnosus, a 42 kDa protease was found in the culture medium. The protease was purified from both S. carnosus (pCAshp1) and S. hyicus subsp. hyicus. The N-terminal amino acid sequences of the two proteases revealed that ShpI is organized as a pre-pro-enzyme with a proposed 26 amino acid signal peptide, a 75 amino acid hydrophilic pro-region, and a 337 amino acid extracellular mature form with a calculated Mr of 38394. The N-termini showed microheterogeneity in both host strains. ShpI had a maximum proteolytic activity at 55°C and pH 7.4–8.5. The protease, which had a low substrate specificity, could be inhibited by metal- and zinc-specific inhibitors, such as EDTA and 1,10-phenanthroline. Insensitivity to phosphoramidon separates ShpI from the thermolysin-like family. The conserved Zn2+ binding motif, the only homology to other proteases, and the reactivation of the apoenzyme by Zn2+, indicated that Zn2+ is the catalytic ion. Ca2+ very probably acts as a stabilizer. We also demonstrated the presence of a second extracellular protease in S. hyicus subsp. hyicus. 相似文献
10.
In a medium containing ammonia, proteose peptone, and cysteine as nitrogen sources, 17 of 24 Bacteroidaceae strains, 3 of Selenomonas strains, 1 of 7 curved rods, 3 of 7 Spirochaetaceae strains, 8 of 20 Eubacterium strains, 8 of 13 Peptococcaceae strains, 3 of 4 Clostridium strains, 19 of 20 Enterobacteriaceae strains, and 1 of 8 Streptococcus strains utilized ammonia nitrogen preferentially to proteose peptone nitrogen. To determine the ability of intestinal microbes to synthesize amino acids from ammonia, ammonia utilization by Bacteroides ruminicola strain 9 was studied in defined media containing ammonia and other nitrogen sources. In another medium containing ammonia, proteose peptone, and cysteine as nitrogen sources, ammonia was preferentially utilized even when the proteose peptone nitrogen content was eight times greater than that of ammonia nitrogen. In a medium containing ammonia, an amino acid, and cysteine, the lowest uptake of ammonia nitrogen was observed when the medium contained aspartic acid, glutamic acid, threonine, or alanine; but ammonia was utilized more effectively than any of the amino acids. Incorporation of 15N from [15N]ammonia into bacterial amino acids was studied. 15N was incorporated into every amino acid of B. ruminicola strain 9, and the highest uptake was observed in aspartic acid and alanine. 相似文献
11.
The contents of amino acids and peptides have been investigated in seeds of Fagus silvatica L. (beechnuts). In addition to the common amino acids, the following compounds have been isolated and identified: 4-hydroxyproline (probably the cis-l-isomer), N5-acetylornithine, 3-(2-furoyl)-l-alanine, methionine sulfoxide (probably an artefact), pipecolic acid (probably partially racemized d-isomer), l-willardiine (with a small amount of the d-isomer), N-(3-amino-3-carboxypropyl)azetidine-2-carboxylic acid, N-[N-(3-amino-3-carboxypropyl)-3-amino-3-carboxypropyl]azetidine-2-carboxylic acid, 2(S),5(S),6(S)-5-hydroxy-6-methylpipecolic acid, 2(S),5(R),6(S)-5-hydroxy-6-methylpipecolic acid, γ-glutamylalanine, γ-glutamylglutamic acid, γ-glutamylisoleucine, γ-glutamylleucine, γ-glutamylmethionine sulfoxide (probably an artefact), γ-glutamylphenylalanine, γ-glutamyltyrosine, γ-glutamylvaline, glutathione, γ-glutamylwillardiine, and γ-glutamylphenylalanylwillardiine. γ-Glutamylphenylalanine and willardiine are the dominating components of the amino acid fraction.The isolations were performed by use of ion exchange chromatography, taking advantage of the different pK-values of the amino acids, mainly on acid resins in the 3-chloropyridinium form with aq. 3-chloropyridine as eluant and on basic resins in the acetate form with aqueous acetic acid as eluant. These methods in combination with preparative paper chromatography have permitted the isolation and identification of compounds present in amounts as low as 1/6000 of the dominant ninhydrin-reactive component. The implications of the occurrence of this large variety of compounds in the Fagaceae are briefly discussed. 相似文献
12.
2(S),3′(S)-N-(3-Amino-3-carboxypropyl)azetidine-2-carboxylic acid and 2(S),3′(S),3″(S)-N-[N-(3-amino-3-carboxypropyl)-3-amino-3-carboxypropyl]azetidine-2-carboxylic acid have been isolated from seeds of Fagus silvatica L. (beechnuts). The structures have been established by PMR- and 13C-NMR-spectroscopy and by synthesis from l-azetidine-2-carboxylic acid. The second of the new amino acids is identical with nicotianamine. previously isolated from Nicotiana tabacum but assigned a different formula. The ring opening reactions of azetidine-2-carboxylic acid in neutral solution have been studied and the chemical and possibly biochemical precursor role of this amino acid for various amino acids including the two new ones described here, nicotianine [N-(3-amino-3-carboxypropyl)nicotinic acid] and methionine is discussed. 相似文献
13.
Two diastereoisomers of 4-carboxy-4-hydroxy-2-aminoadipic acid have been isolated from leaves and inflorescences of Caylusea abyssinica. Green parts of the plant also contain appreciable amounts of the two diastereoisomers of 4-hydroxy-4-methylglutamic acid, 3-(3-carboxyphenyl)alanine, (3-carboxyphenyl)glycine, 3-(3-carboxy-4-hydroxyphenyl)alanine, (3-carboxy-4-hydroxyphenyl)glycine and in low concentration 2-aminoadipic acid, saccharopine [(2S, 2′S)-N6-(2-glutaryl)lysine] and some γ-glutamyl peptides. The acidic amino acids were separated from other amino acids on an Ecteola ion exchange column with M pyridine as eluant. 相似文献
14.
《International journal of radiation applications and instrumentation. Part B, Nuclear medicine and biology》1990,17(4):369-376
Using 11C-labeled natural amino acids, the functional diagnosis of tissue metabolism has been actively studied. Our interest has been focused on developing a clinically available 123I-labeled artificial amino acid with a single metabolic function. For this study, [123I]3-iodo-d-tyrosine ([123I]d-MIT) was selected. In vitro and in vivo studies using 125I-labeled d-MIT indicated that it showed a high pancreatic accumulation, selective affinity for membrane active transport systems, and was stable against enzymatic deiodination. A canine scintigraphic study using 123I-labeled d-MIT and kinetic analysis showed that it behaved as an “artificial amino acid” radiopharmaceutical with selective membrane amino acid transport affinity in the pancreas. 相似文献
15.
A novel acidic amino acid present in crown gall tumours induced on Nicotiana tabacum cv White Burley by Agrobacterium tumefaciens has been identified as N2-(1,3-dicarboxypropyl) ornithine. 相似文献
16.
Peder Olesen Larsen Hilmer Sørensen David W. Cochran Edward W. Hagaman Ernest Wenkert 《Phytochemistry》1973,12(7):1713-1719
2(S),4(R)-4-(β-d-Galactopyranosyloxy)-4-isobutylglutamic acid (I) has been isolated from the flowers of Reseda odorata, wherein it occurs in substantial quantity. Hydrolysis of I gives d-galactose, 2(S),4(R)-4-hydroxy-4-isobutylglutamic acid (II) and 3(R),5(S)-3-hydroxy-3-isobutyl-2-pyrrolidone-5-carboxylic acid (III) and its treatment with nitrous acid yields a galactoside of a non-nitrogenous hydroxy acid lactone (IV). The structures of I and its degradation products are supported by PMR, 13C-NMR and other spectroscopic methods. 13C-NMR spectroscopy of the model compound 2-(β-d-galactopyranosyloxy)isobutyric acid confirmed the structure of the natural product. The S- (or l-) configuration at C(2) in the amino acid moiety of I has been established by the use of the Clough—Lutz—Jirgenson rule and the R-configuration at C(4) of the same unit has been assigned tentatively. I represents the first example of a glycoside of a higher plant amino acid in which the carbohydrate residue is linked to an aliphatic hydroxy group. 相似文献
17.
《Journal of Molecular Catalysis .B, Enzymatic》1999,6(3):359-367
Several microorganisms that can use (S)-5-[(amino-iminomethyl) amino]-2-chloropentanoic acid (l-Cl-arginine) as a nitrogen source have been isolated, the most interesting of which is a spontaneous mutant of Pseudomonas aeruginosa PAO1 (DSM 10581). In a fermenter, this unique biocatalyst hydrolysed l-Cl-arginine to (S)-5-amino-2-chloropentanoic acid (l-Cl-ornithine), which spontaneously converted to d-proline with inversion of configuration at an apparent average rate of 0.12 mmol −l h−1 OD−1. The enzyme, for which we suggest the name Cl-arginine amidinohydrolase, was best induced by using the substrate l-Cl-arginine as inducer and l-arginine as nitrogen source. The results presented here describe a new route for the production of d-proline from l-arginine, involving a chemical step and a biocatalytic step followed by a spontaneous chemical cyclisation. 相似文献
18.
Jae-Hong Ko Marwa Ahmed Ibrahim Won Sun Park Nari Kim Inja Lim Jin Han 《Biochemical and biophysical research communications》2009,389(1):74-79
Large-conductance Ca2+-activated K+ (BKCa) channels are widely distributed in cellular membranes of various tissues, but have not previously been found in cardiomyocytes. In this study, we cloned a gene encoding the mouse cardiac BKCa channel α-subunit (mCardBKa). Sequence analysis of the cDNA revealed an open reading frame encoding 1154 amino acids. Another cDNA variant, identical in amino acid sequence, was also identified by sequence analysis. The nucleotide sequences of the two mCardBKa cDNAs, type 1 (mCardBKa1) and type 2 (mCardBKa2), differed by three nucleotide insertions and one nucleotide substitution in the N-terminal sequence. The amino acid sequence demonstrated that mCardBKa was a unique BKCa channel α-subunit in mouse cardiomyocytes, with amino acids 41-1153 being identical to calcium-activated potassium channel SLO1 and amino acids 1-40 corresponding to BKCa channel subfamily M alpha member 1. These findings suggest that a unique BKCa channel α-subunit is expressed in mouse cardiomyocytes. 相似文献
19.
Tzong-Shin Lin P.E. Kolattukudy 《Biochemical and biophysical research communications》1977,75(1):87-93
Treatment of cutinase, an extracellular glycoprotein produced by Fusarium solani f. pisi, with NaB3H4 at pH 7.0 generated labeled enzyme. Acid hydrolysis showed that all of the label was in an acidic carbohydrate which was identified as gulonic acid. The N-terminal amino group of the enzyme is blocked; the precursor of gulonic acid has a free reducing group and it is attached via a linkage resistant to β-elimination. Furthermore, pronase digestion of NaB3H4-treated cutinase gave rise to a ninhydrin negative compound which contained the bulk of the 3H and this compound was identified as N-gulonyl glycine. These results strongly suggest that the amino group of glycine, the N-terminal amino acid of this enzyme, is in amide linkage with glucuronic acid. 相似文献
20.
Amino Acid Metabolism of Lemna minor L. : IV. N-Labeling Kinetics of the Amide and Amino Groups of Glutamine and Asparagine
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A serious limitation to the use of N(O,S)-heptafluorobutyryl isobutyl amino acid derivatives in the analysis of 15N-labeling kinetics of amino acids in plant tissues, is that the amides glutamine and asparagine undergo acid hydrolysis to glutamate and aspartate, respectively, during derivatization. This led us to consider an alternative procedure (G Fortier et al. [1986] J Chromatogr 361: 253-261) for derivatization of glutamine and asparagine with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide in pyridine. Gas chromatography-mass spectrometry (electron ionization) yielded fragment ions (M-57) of mass 417 and 431 for the [14N]asparagine and [14N]glutamine derivatives, respectively, suitable for monitoring unlabeled, single-15N- and double-15N-labeled amide species from the ion clusters at mass to charge ratio (m/z) 415 to 423 for asparagine, and m/z 429 to 437 for glutamine. From separate analyses of the specific isotope abundance of the amino-N groups of asparagine and glutamine as their N-heptafluorobutyryl isobutyl derivatives, the specific amide-[15N] abundance of these amino acids was determined. We demonstrate that this approach to 15N analysis of the amides can yield unique insights as to the compartmentation of asparagine and glutamine in vivo. The ratios of unlabeled:single-15N:double-15N-labeled species are highly diagnostic of the relative sizes and turnover of metabolically active and inactive pools of the amides and their precursors. Kinetic evidence is presented to indicate that a significant proportion (approximately 10%) of the free asparagine pool may be metabolically inactive (vacuolar). If the amide group of asparagine is derived exclusively from glutamine-amide, then asparagine must be synthesized in a compartment of the cell in which both glutamine-amide and aspartate are more heavily labeled with 15N than the bulk pools of these amino acids. This compartment is presumably the chloroplast. The transaminase inhibitor aminooxyacetate is shown to markedly inhibit amino acid synthesis; several amino acid pools accumulated in the presence of aminooxyacetate and [15N]H4+ are 14N-enriched and must be derived primarily from protein turnover. 相似文献