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1.
Corina Seibold Helge Schnerr Julia Rumpf Andrea Kunzendorf Catharina Hatscher Tobias Wage 《Biocatalysis and Biotransformation》2013,31(6):401-408
Regioselective halogenation of electron rich substrates is catalysed by flavin-dependent halogenases. Thienodolin produced by Streptomyces albogriseolus contains a chlorine atom in the 6-position of the indole ring system and is believed to be derived from tryptophan. Using the gene of the tryptophan 7-halogenase (PrnA) from the pyrrolnitrin biosynthetic gene cluster the gene for a tryptophan 6-halogenase was cloned, sequenced and heterologously overexpressed in Pseudomonas strains. In vitro activity of the purified enzyme could only be shown in a two-component enzyme system consisting of the halogenase, a flavin reductase, NADH, FAD and halide ions. The enzyme catalyses the regioselective chlorination and bromination of l- and d-tryptophan. In its native form the enzyme is probably a homodimer with a relative molecular mass of the subunits of 63 600 (including the His-tag). Transformation of the pyrrolnitrin producer Pseudomonas chlororaphis ACN with a plasmid containing the tryptophan 6-halogenase gene lead to the formation of the new aminopyrrolnitrin derivative 3-(2′-amino-4′-chlorophenyl) pyrrole. 相似文献
2.
《Bioscience, biotechnology, and biochemistry》2013,77(9):2128-2130
Dibenzothiophene monooxygenase (BdsC) from Bacillus subtilis WU-S2B utilized aromatic compounds not having sulfur atoms as substrates. It acted on indole and its derivatives to form indigoid pigments, and also utilized indoline and phenoxazine. In addition, BdsC exhibited activity toward benzothiophene (BT) derivatives but not BT, suggesting that it shows wide reactivity toward aromatic compounds. 相似文献
3.
Degradation of indole by enrichment culture and Pseudomonas aeruginosa Gs isolated from mangrove sediment 总被引:1,自引:1,他引:0
Microbial degradation of indole was investigated using enrichment culture and Pseudomonas aeruginosa Gs obtained from mangrove sediment of Hong Kong Nature Reserve as inocula. Degradation of indole using this enrichment culture and Ps. aeruginosa Gs was quantified on reversed-phase high-performance liquid chromatography. Initial concentrations of indole affected degradation and the results conformed to the zero-order kinetic model. The optimum pH and salinity were 7.0 and 5‰, respectively, for indole degradation by Ps. aeruginosa Gs. Two major metabolites of indole degradation were detected. This study suggests that indole can be rapidly degraded by indigenous microorganisms of the mangrove environment. 相似文献
4.
The reactions of the indole analogues indoline and aniline with the Escherichia coli tryptophan synthase alpha-aminoacrylate Schiff base intermediate have been characterized by UV-visible and 1H NMR absorption spectroscopy and compared with the interactions of indole and the potent inhibitor benzimidazole. Indole, via the enamine functionality of the pyrrole ring, reacts with the alpha-aminoacrylate intermediate, forming a transient quinonoid species with lambda max 476 nm as the new C-C bond is synthesized. Conversion of this quinonoid to L-tryptophan is the rate-limiting step in catalysis [Lane, A., & Kirschner, K. (1981) Eur. J. Biochem. 120, 379-398]. Both aniline and indoline undergo rapid N-C bond formation with the alpha-aminoacrylate to form quinonoid intermediates; benzimidazole binds rapidly and tightly to the alpha-aminoacrylate but does not undergo covalent bond formation. The indoline and aniline quinonoids (lambda max 464 and 466 nm, respectively) are formed via nucleophilic attack on the electrophilic C-beta of the alpha-aminoacrylate. The indoline quinonoid decays slowly, yielding a novel, new amino acid, dihydroisotryptophan. The aniline quinonoid is quasi-stable, and no new amino acid product was detected. We conclude that nucleophilic attack requires the precise alignment of bonding orbitals between nucleophile and the alpha-aminoacrylate intermediate. The constraints imposed by the geometry of the indole subsite force the aromatic rings of indoline, aniline, and benzimidazole to bind in the same plane as indole; thus nucleophilic attack occurs with the N-1 atoms of indoline and aniline.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
5.
Iou-Jiun Kang Li-Wen Wang Sheng-Ju Hsu Chung-Chi Lee Yen-Chun Lee Yen-Shian Wu Tsu-An Hsu Andrew Yueh Yu-Sheng Chao Jyh-Haur Chern 《Bioorganic & medicinal chemistry letters》2009,19(15):4134-4138
An efficient synthetic methodology to provide indole, 2,3-dihydro-indole, and 3,4-dihydro-2H-quinoline-1-carbothioic acid amide derivatives is described. These conformationally restricted heterobicyclic scaffolds were evaluated as a novel class of HCV inhibitors. Introduction of an acyl group at the NH2 of the thiourea moiety has been found to enhance inhibitory activity. The chain length and the position of the alkyl group on the indoline aromatic ring markedly influenced anti-HCV activity. The indoline scaffold was more potent than the corresponding indole and tetrahydroquinoline scaffolds and analogue 31 displayed excellent activity (EC50 = 510 nM) against HCV without significant cytotoxicity (CC50 >50 μM). 相似文献
6.
Partial hydrolysis of triacylglycerols of high-erucic-acid seed oils from white mustard (Sinapis alba), oriental mustard (Brassica juncea) and honesty (Lunaria annua), catalysed by lipases from Candida cylindracea and Geotrichum candidum, leads to enrichment of erucic acid and other very-long-chain mono-unsaturated fatty acids (VLCMFA) in the acylglycerols (mono-, di- and triacylglycerol) while the C18 fatty acids (oleic, linoleic and linolenic) are enriched in the fatty acid fraction. Partial hydrolysis of the high-erucic-acid triacylglycerols, catalysed by lipases from porcine pancreas, Chromobacterium viscosum, Rhizopus arrhizus and Rhizomucor miehei yields fatty acids with substantially higher levels of VLCMFA, as compared to the starting material, while the C18 fatty acids are enriched in the acylglycerol fraction. Lipases from Penicillium sp. and Candida antarctica are ineffective for the fractionation of either group of fatty acids. Transesterification of the high-erucic-acid triacylglycerols with ethyl, propyl or butyl acetate or with n-butanol, catalysed by the lipase from R. miehei, leads to enrichment of VLCMFA in the alkyl (ethyl, propyl or butyl) esters, whereas the C18 fatty acids are enriched in the acetylacylglycerols and acylglycerols. 相似文献
7.
Grégory Guirimand Vincent Courdavault Arnaud Lanoue Samira Mahroug Anthony Guihur Nathalie Blanc Nathalie Giglioli-Guivarc'h Benoit St-Pierre Vincent Burlat 《BMC plant biology》2010,10(1):182
Background
The first two enzymatic steps of monoterpene indole alkaloid (MIA) biosynthetic pathway are catalysed by strictosidine synthase (STR) that condensates tryptamine and secologanin to form strictosidine and by strictosidine β-D-glucosidase (SGD) that subsequently hydrolyses the glucose moiety of strictosidine. The resulting unstable aglycon is rapidly converted into a highly reactive dialdehyde, from which more than 2,000 MIAs are derived. Many studies were conducted to elucidate the biosynthesis and regulation of pharmacologically valuable MIAs such as vinblastine and vincristine in Catharanthus roseus or ajmaline in Rauvolfia serpentina. However, very few reports focused on the MIA physiological functions. 相似文献8.
The stereoselective synthesis of cathepsin inhibitors from indoline type epoxyamides is described. The use of this type of epoxyamides permitted the preparation of E-64 and CA-074 related compounds depending on the order in which the key steps, the oxidation of indoline amides to indole amides and oxidative acetal cleavage were undertaken. By taking advantage of the facile substitution of the indole of the corresponding indole epoxyamides, with various nucleophiles, we were able to prepare different epoxysuccinic acids derivatives as potential cathepsin inhibitors. 相似文献
9.
10.
The importance of five amino acids at the active site of the multicomponent naphthalene dioxygenase (NDO) system was determined
by generating site-directed mutations in various combinations. The substrate specificities of the mutant enzymes were tested
with the substrates indole, indoline, 2-nitrotoluene (2NT), naphthalene, biphenyl, and phenanthrene. Transformation of these
substrates measured the ability of the mutant enzymes to catalyze dioxygenation, monooxygenation, and desaturation reactions.
In addition, the position of oxidation and the enantiomeric composition of products were characterized. All enzymes with up
to three amino acid substitutions were able to catalyze dioxygenation reactions. A subset of these enzymes could also catalyze
the monooxygenation of 2NT and desaturation of indoline. Single amino acid substitutions at positions 352 and 206 had the
most profound effects on product formation. Of the single mutations made, only changes at position 352 affected the stereochemistry
of naphthalene cis-dihydrodiol formed from naphthalene, but in the presence of the F352I mutation, changes at positions 206 and 295 also affected
enantioselectivity. Major shifts in regioselectivity with biphenyl and phenanthrene resulted with several of the singly, doubly,
and triply mutated enzymes. A new product not formed by the wild-type enzyme, phenanthrene cis-9,10-dihydrodiol, was formed as a major product from phenanthrene by enzymes with two (A206I/F352I) or three amino acid substitutions
(A206I/F352I/H295I). The results indicate that a variety of amino acid substitutions are tolerated at the active site of NDO.
Journal of Industrial Microbiology & Biotechnology (2001) 27, 94–103.
Received 25 September 2000/ Accepted in revised form 29 June 2001 相似文献
11.
A bromoperoxidase was isolated from the chlortetracycline-producing actinomycete, Streptomyces aureofaciens. This enzyme catalysed bromination and iodination, but surprisingly did not catalyse chlorination. The enzyme had an acidic pH optimum (pH 4.3) and the isoelectric point was 3.5. The Km for bromide was 20 mM and the Km for H2O2 was as high as 8 mM. The bromoperoxidase did not contain haem, since it was not inhibited by azide or cyanide. Excess bromide or chloride had no effect on its brominating activity; however, fluoride strongly inhibited the bromoperoxidase (Ki = 20 microM). On the basis of gel electrophoresis in the absence and presence of sodium dodecyl sulphate, the molecular mass of the enzyme was 65 kDa and it consisted of two subunits of 32 kDa each. The bromoperoxidase was remarkably thermostable. 相似文献
12.
A novel regulatory circuit to control indole biosynthesis protects Escherichia coli from nitrosative damages during the anaerobic respiration of nitrate
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Indole is a widely distributed microbial secondary metabolite. It mediates a broad range of physiological processes in both its producing and surrounding species. Yet, indole biosynthesis during the anaerobiosis of bacteria remains largely uncharacterized. Here, we find that while indole production is promoted during fermentation and anaerobic respiration of fumarate and trimethylamine N‐oxide in E. coli, its biosynthesis is repressed during anaerobic respiration of nitrate especially during exponential growth. We show that expression of the indole biosynthetic operon tnaCAB is repressed under this condition by the two component systems NarXL and NarPQ in the global regulator FNR dependent manner. During stationary growth phase of nitrate respiration, indole biosynthesis is derepressed. However, cellular indole concentration remains low. We demonstrate that this is due to the rapid conversion of indole into mutagenic indole nitrosative derivatives under this condition. Consistent with this, a supplement of exogenous indole during nitrate respiration causes elevated mutation frequencies in E. coli cells lacking the detoxifying efflux genes mdtEF, and ectopic over‐expression of tnaAB genes decreases the fitness of E. coli to this physiological condition. Together, these results suggest that indole production is tuned to the bioenergetics activities of E. coli to facilitate its adaptation and fitness. 相似文献
13.
Two dimethylallyltryptophan synthases, FgaPT2 and 7-DMATS, which catalysed the prenylation of l-tryptophan at positions C4 and C7, respectively, have been recently identified in Aspergillus fumigatus and proven biochemically. These enzymes were successfully used for the production of monoprenylated indole derivatives. In
this study, we showed that C4,C7-diprenylated indole derivatives, e.g. 4,7-di-(dimethylallyl)-l-tryptophan, 4,7-di-(dimethylallyl)-l-abrine and 4,7-di-(dimethylallyl)-11-methyltryptophan, could be conveniently produced by tandem incubation of both enzymes.
The structures of the isolated enzymatic products were elucidated by NMR and MS analyses. High conversion yields of up to
93% were achieved by an incubation sequence of FgaPT2 followed by 7-DMATS. The results reported in this study demonstrated
the potential of secondary metabolite enzymes as promising tools for the production of designed compounds. 相似文献
14.
Nicolas Denancé Philippe Ranocha Nicolas Oria Xavier Barlet Marie‐Pierre Rivière Koste A. Yadeta Laurent Hoffmann François Perreau Gilles Clément Alessandra Maia‐Grondard Grardy C.M. van den Berg Bruno Savelli Sylvie Fournier Yann Aubert Sandra Pelletier Bart P.H.J. Thomma Antonio Molina Lise Jouanin Yves Marco Deborah Goffner 《The Plant journal : for cell and molecular biology》2013,73(2):225-239
15.
Yan Xing Hongyun Peng Lingling Gao Ancheng Luo Xiaoe Yang 《International journal of phytoremediation》2013,15(10):952-964
Sedum alfredii Hance is a fast-growing and high-biomass zinc (Zn) hyperaccumulator native to China. A compound containing substituted indole ligand was isolated from this Zn hyperaccumulator plants by sonication/ethanol extraction, macroporous resin column as well as preparative HPLC (P-HPLC). Hydroponic experiment showed that the concentrations of both Zn and the compound containing substituted indole ligand were remarkably increased in stems and leaves of both hyperaccumulator and non-hyperaccumulator as Zn rising from 0.5 to 50 μmol L?1, with much more in the stems of hyperaccumulator than non-hyperaccumulator. At 50 μmol L?1 Zn, hyperaccumulator grew normally but its non-hyperaccumulator suffered from strongly Zn-induced toxicity. This suggested that there was a positive correlation between the compound containing substituted indole ligand and Zn concentration in shoots of hyperaccumulator S. alfredii. 相似文献
16.
《Biocatalysis and Biotransformation》2013,31(2-3):177-183
The selective enzymatic hydrolysis of 3′,5′-di-O-acetylthyidine (1) was studied. The lipases from porcine pancreas and Aspergillus niger, and pig liver esterase, all catalysed selective hydrolysis of the 5′O-acetyl group, but the lipase from Candida cylindracea catalysed selective hydrolysis of the 3′-O-acetyl group. Highest selectivity, leading to essentially pure 3′-O-acetylthymidine, was achieved using porcine pancreatic lipase in dilute solution at pH 7.5. Provision of an artificial interface in the form of polystyrene beads led to a significant increase in the rate of hydrolysis, accompanied by a marked fall in selectivity. Other changes in the hydrolysis conditions, such as raising the concentration of substrate or adding cosolvent, also led to a fall in selectivity. 相似文献
17.
Sano H Noguchi T Tanatani A Hashimoto Y Miyachi H 《Bioorganic & medicinal chemistry》2005,13(9):3079-3091
A series of substituted indoline and indole derivatives with cyclooxygenase (COX)-inhibitory activity was prepared during our structural development studies based on thalidomide as a multi-template lead compound. Structure-activity relationship studies indicated that the nature of the substituent introduced at the benzene ring of the indoline (indole) backbone, and the length and type of the linking group between the nitrogen atom of indoline (indole) and the N-substituent are important for the activity. This study has led to the identification of COX-1-selective inhibitors, and these should be useful not only as pharmacological tools to investigate the physiology and pathophysiology of COX, but also as sophisticated leads for the development of novel drugs to treat COX-associated diseases, such as inflammatory diseases, and cancer. 相似文献
18.
The potent anticancer and antiviral compound camptothecin (CPT) is a monoterpene indole alkaloid produced by Camptotheca acuminata. In order to investigate the biosynthetic pathway of CPT, we studied the early indole pathway, a junction between primary and secondary metabolism, which generates tryptophan for both protein synthesis and indole alkaloid production. We cloned and characterized the alpha subunit of anthranilate synthase (ASA) from Camptotheca (designated CaASA), catalyzing the first committed reaction of the indole pathway. CaASA is encoded by a highly conserved gene family in Camptotheca. The two CaASA genes are differentially regulated. The level of CaASA2 is constitutively low in Camptotheca and was found mainly in the reproductive tissues in transgenic tobacco plants carrying the CaASA2 promoter and -glucuronidase gene fusion. CaASA1 was detected to varying degrees in all Camptotheca organs examined and transiently induced to a higher level during seedling development. The spatial and developmental regulation of CaASA1 paralleled that of the previously characterized Camptotheca gene encoding the beta subunit of tryptophan synthase as well as the accumulation of CPT. These data suggest that CaASA1, rather than CaASA2, is responsible for synthesizing precursors for CPT biosynthesis in Camptotheca and that the early indole pathway and CPT biosynthesis are coordinately regulated. 相似文献
19.
Yuji Kamiya Akira Sakurai Saburo Tamura Keiko Abe Eiko Tsuchiya Sakuzo Fukui 《Bioscience, biotechnology, and biochemistry》2013,77(6):1099-1100
Two cosmid clones containing distinct types of self-defense gene of a 6-demethylchlortetracycline producer, Streptomyces aureofaciens NRRL3203, were isolated. The gene responsible for chlorination of tetracycline (chl gene) was subcloned from one of the cosmid clones by complementation of a chlorination-deficient mutant, using a gene cloning system for strain NRRL3203 developed in this study. The nucleotide sequence analysis of a 4.4-kb SacI-BamHI fragment containing the chl gene showed that the predicted product of the chl gene is a polypeptide of 452 amino acids, and that the chl gene was preceded by two open reading frames, which could endode polypeptides of 50 kDa and 32 kDa, respectively. A search for sequences homologous to these ORFs found that the former product strongly resembles that of the 6-hydroxylation enzyme for oxytetracycline biosynthesis, and that the latter product has a weak but significant similarity to the hydroxy indole O-methyltransferase of bovine pineal gland. By Northern blot analysis, these three genes were suggested to be polycistronically transcribed. 相似文献
20.
Hoshino T 《Applied microbiology and biotechnology》2011,91(6):1463-1475
Violacein is a natural violet pigment produced by several Gram-negative bacteria, including Chromobacterium violaceum, Janthinobacterium lividum, and Pseudoalteromonas tunicata D2, among others. This pigment has potential medical applications as antibacterial, anti-trypanocidal, anti-ulcerogenic,
and anticancer drugs. The structure of violacein consists of three units: a 5-hydroxyindole, an oxindole, and a 2-pyrrolidone.
The biosynthetic origins of hydrogen, nitrogen, and carbon in the pyrrolidone nucleus were established by feeding experiments
using various stable isotopically labeled tryptophans (Trps). Pro-S hydrogen of CH2 at the 3-position of Trp is retained during biosynthesis. The nitrogen atom is exclusively from the α-amino group, and the
skeletal carbon atoms originate from the side chains of the two Trp molecules. All three oxygen atoms in the violacein core
are derived from molecular oxygen. The most interesting biosynthetic mechanism is the 1,2-shift of the indole nucleus on the
left side of the violacein scaffold. The alternative Trp molecule is directly incorporated into the right side of the violacein
core. This indole shift has been observed only in violacein biosynthesis, despite the large number of natural products having
been isolated. There were remarkable advances in biosynthetic studies in 2006–2008. During the 3 years, most of the intermediates
and the complete pathway were established. Two independent processes are involved: the enzymatic process catalyzed by the
five proteins VioABCDE or the alternative nonenzymatic oxidative decarboxylation reactions. The X-ray crystallographic structure
of VioE that mediates the indole rearrangement reaction was recently identified, and the mechanism of the indole shift is
discussed here. 相似文献