392-12-1Relevant articles and documents
Stereospecific biosynthesis of β-methyltryptophan from L-tryptophan features a stereochemical switch
Zou, Yi,Fang, Qi,Yin, Haixing,Liang, Zutao,Kong, Dekun,Bai, Linquan,Deng, Zixin,Lin, Shuangjun
, p. 12951 - 12955 (2013)
Make the switch: The three-enzyme cassette MarG/H/I is responsible for stereospecific biosynthesis of β-methyltryptophan from L-tryptophan (1). MarG/I convert 1 into (2S,3R)-β-methyltryptophan, while MarG/I combined with MarH convert 1 into (2S,3S)-β-methyltryptophan. MarH serves as a stereochemical switch by catalyzing the stereoinversion of the β-stereocenter. Copyright
A Novel Enzyme, L-Tryptophan Oxidase, from a Basidiomycete, Coprinus sp. SF-1: Purification and Characterization
Furuya, Yuji,Sawada, Hidemi,Hirahara, Toshikatsu,Ito, Kazue,Ohshiro, Takashi,Izumi, Yoshikazu
, p. 1486 - 1493 (2000)
A basidiomycete, Coprinus sp. SF-1, was found to produce an L-Trp-oxidizing enzyme by screening from the culture collection of our laboratory. After solubilization by 1 M NaSCN from the participate fraction of disrupted cells of the strain, the enzyme was purified about 76-fold to essential homogeneity. The enzyme had a molecular mass of about 420 kDa and the subunit molecular mass was 68 kDa. The enzyme contained 1 mol of non-covalently bound FAD per mol of the subunit. It catalyzed the simultaneous reactions of oxidative deamination and oxygenative decarboxylation of L-Trp to form indolepyruvic acid and indole-3-acetamide, the former of which was further oxidized to indole-3-acetic acid. The molar ratio of the respective reaction products was about 9:1. The enzyme specifically oxidized L-Trp, and slightly acted on L-Phe and L-Tyr. The Km for L-Trp was about 0.5 mM in both oxidase and oxygenase reactions. Thus, the enzyme is a novel one and was tentatively designated L-Trp oxidase (deaminating and decarboxylating) . The optimum pHs of oxidase and oxygenase activities were 7.0 and 9.0, respectively. The optimum temperatures of both activities were 50°C. The enzyme was stable at pH 6.0-10.5 and below 50°C, and at 4°C for 1 year.
Production of α-Ketoisocaproate and α-Keto-β-Methylvalerate by Engineered L-Amino Acid Deaminase
Yuan, Yuxiang,Song, Wei,Liu, Jia,Chen, Xiulai,Luo, Qiuling,Liu, Liming
, p. 2464 - 2472 (2019/05/10)
This study aimed to develop an efficient enzymatic strategy for industrial production of α-ketoisocaproate (α-KIC) and α-keto-β-methylvalerate (α-KMV) from L-leucine and L-isoleucine, respectively. L-amino acid deaminase from Proteus mirabilis (PmLAAD) was heterologously expressed in E. coli BL21(DE3) and modified to increase its catalytic efficiency by engineering the PmLAAD substrate-binding cavity and entrance tunnel. Four essential residues (Q92, M440, T436, and W438) were identified from structural analysis and molecular dynamics simulations. Residue Q92 was mutated to alanine, and the volume of the binding cavity, enzyme activity, and the kcat/Km value of mutant PmLAAD Q92A increased to 994.2 ?3, 191.36 U mg?1, and 1.23 mM?1 min?1, respectively; consequently, the titer and conversion rate of α-KIC from L-leucine were 107.1 g L?1 and 98.1 %, respectively. For mutant PmLAADT436/W438A, the entrance tunnel, enzyme activity, and the kcat/Km value increased to 1.71 ?, 170.12 U mg?1, and 0.70 mM?1 min?1, respectively; consequently, the titer and conversion rate of α-KMV from L-isoleucine were 98.9 g L?1 and 99.7 %, respectively. Therefore, augmentation of the substrate-binding cavity and entrance tunnel of PmLAAD can facilitate efficient industrial synthesis of α-KIC and α-KMV.
The pseudoalteromonas luteoviolacea L-amino acid oxidase with antimicrobial activity is a flavoenzyme
Andreo-Vidal, Andrés,Sanchez-Amat, Antonio,Campillo-Brocal, Jonatan C.
, (2019/01/03)
The marine environment is a rich source of antimicrobial compounds with promising pharmaceutical and biotechnological applications. The Pseudoalteromonas genus harbors one of the highest proportions of bacterial species producing antimicrobial molecules. For decades, the presence of proteins with L-amino acid oxidase (LAAO) and antimicrobial activity in Pseudoalteromonas luteoviolacea has been known. Here, we present for the first time the identification, cloning, characterization and phylogenetic analysis of Pl-LAAO, the enzyme responsible for both LAAO and antimicrobial activity in P. luteoviolacea strain CPMOR-2. Pl-LAAO is a flavoprotein of a broad substrate range, in which the hydrogen peroxide generated in the LAAO reaction is responsible for the antimicrobial activity. So far, no protein with a sequence similarity to Pl-LAAO has been cloned or characterized, with this being the first report on a flavin adenine dinucleotide (FAD)-containing LAAO with antimicrobial activity from a marine microorganism. Our results revealed that 20.4% of the sequenced Pseudoalteromonas strains (specifically, 66.6% of P. luteoviolacea strains) contain Pl-laao similar genes, which constitutes a well-defined phylogenetic group. In summary, this work provides insights into the biological significance of antimicrobial LAAOs in the Pseudoalteromonas genus and shows an effective approach for the detection of novel LAAOs, whose study may be useful for biotechnological applications.
Kinetics and mechanism of the condensation of pyridoxal hydrochloride with L-tryptophan and D-tryptophan, and the chemical transformation of their products
Pishchugin,Tuleberdiev
, p. 1851 - 1854 (2017/09/27)
The kinetics and mechanism of interaction between pyridoxal and L-tryptophan, D-tryptophan, and their derivatives are studied. It is found that condensation reactions proceed via three kinetically distinguishable stages: (1) the rapid intraplanar addition of the NH2 groups of the amino acids to pyridoxal with the formation of amino alcohols; (2) the rotational isomerism of amino alcohol fragments with their subsequent dehydration and the formation of a Schiff base with a specific configuration; (3) the abstraction of α-hydrogen in the product of condensation of pyridoxal with L-tryptophan, or the abstraction of СО2 in the product of condensation of pyridoxal with D-tryptophan with the formation of quinoid structures, hydrolysis of which results in the preparation of pyridoxamine and keto acid or pyridoxal and tryptamine, respectively. Schiff bases resistant to further chemical transformations are formed in the reaction with tryptophan methyl ester.
Processing 2-Methyl- l -Tryptophan through Tandem Transamination and Selective Oxygenation Initiates Indole Ring Expansion in the Biosynthesis of Thiostrepton
Lin, Zhi,Ji, Jia,Zhou, Shuaixiang,Zhang, Fang,Wu, Jiequn,Guo, Yinlong,Liu, Wen
, p. 12105 - 12108 (2017/09/12)
Thiostrepton (TSR), an archetypal member of the family of ribosomally synthesized and post-translationally modified thiopeptide antibiotics, possesses a biologically important quinaldic acid (QA) moiety within the side-ring system of its characteristic thiopeptide framework. QA is derived from an independent l-Trp residue; however, its associated transformation process remains poorly understood. We here report that during the formation of QA, the key expansion of an indole to a quinoline relies on the activities of the pyridoxal-5′-phosphate-dependent protein TsrA and the flavoprotein TsrE. These proteins act in tandem to process the precursor 2-methyl- l-Trp through reversible transamination and selective oxygenation, thereby initiating a highly reactive rearrangement in which selective C2-N1 bond cleavage via hydrolysis for indole ring-opening is closely coupled with C2′-N1 bond formation via condensation for recyclization and ring expansion in the production of a quinoline ketone intermediate. This indole ring-expansion mechanism is unusual, and represents a new strategy found in nature for l-Trp-based functionalization.
Polypeptides and biosynthetic pathways
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Paragraph 0163, (2016/08/23)
Methods and compositions that can be used to make monatin from glucose, tryptophan, indole-3-lactic acid, indole-3-pyruvate, and 2-hydroxy 2-(iridol-3-ylmethyl)-4-keto glutaric acid, are provided. Methods are also disclosed for producing the indole-3-pyruvate and 2-hydroxy 2-(indol-3ylmethyl)-4-keto glutaric acid intermediates. Compositions provided include nucleic acid molecules, polypeptides, chemical structures, and cells. Methods include in vitro and in vivo processes, and the in vitro methods include chemical reactions.
Tryptophan Lyase (NosL): A Cornucopia of 5′-Deoxyadenosyl Radical Mediated Transformations
Bhandari, Dhananjay M.,Fedoseyenko, Dmytro,Begley, Tadhg P.
supporting information, p. 16184 - 16187 (2016/12/27)
Tryptophan lyase (NosL) is a radical S-adenosyl-l-methionine (SAM) enzyme that catalyzes the formation of 3-methyl-2-indolic acid from l-tryptophan. In this paper, we demonstrate that the 5′-deoxyadenosyl radical is considerably more versatile in its chem
Characterization of aromatic aminotransferases from Ephedra sinica Stapf
Kilpatrick, Korey,Pajak, Agnieszka,Hagel, Jillian M.,Sumarah, Mark W.,Lewinsohn, Efraim,Facchini, Peter J.,Marsolais, Frédéric
, p. 1209 - 1220 (2016/04/26)
Ephedra sinica Stapf (Ephedraceae) is a broom-like shrub cultivated in arid regions of China, Korea and Japan. This plant accumulates large amounts of the ephedrine alkaloids in its aerial tissues. These analogs of amphetamine mimic the actions of adrenaline and stimulate the sympathetic nervous system. While much is known about their pharmacological properties, the mechanisms by which they are synthesized remain largely unknown. A functional genomics platform was established to investigate their biosynthesis. Candidate enzymes were obtained from an expressed sequence tag collection based on similarity to characterized enzymes with similar functions. Two aromatic aminotransferases, EsAroAT1 and EsAroAT2, were characterized. The results of quantitative reverse transcription-polymerase chain reaction indicated that both genes are expressed in young stem tissue, where ephedrine alkaloids are synthesized, and in mature stem tissue. Nickel affinity-purified recombinant EsAroAT1 exhibited higher catalytic activity and was more homogeneous than EsAroAT2 as determined by size-exclusion chromatography. EsAroAT1 was highly active as a tyrosine aminotransferase with α-ketoglutarate followed by α-ketomethylthiobutyrate and very low activity with phenylpyruvate. In the reverse direction, catalytic efficiency was similar for the formation of all three aromatic amino acids using l-glutamate. Neither enzyme accepted putative intermediates in the ephedrine alkaloid biosynthetic pathway, S-phenylacetylcarbinol or 1-phenylpropane-1,2-dione, as substrates.
Biocontrolled formal inversion or retention of L -α-amino acids to enantiopure (R)- or (S)-hydroxyacids
Busto, Eduardo,Grischek, Barbara,Kroutil, Wolfgang,Richter, Nina
supporting information, p. 11225 - 11228,4 (2015/01/07)
Natural L-α-amino acids and L-norleucine were transformed to the corresponding α-hydroxy acids by formal biocatalytic inversion or retention of absolute configuration. The one-pot transformation was achieved by a concurrent oxidation reduction cascade in aqueous media. A representative panel of enantiopure (R)- and (S)-2-hydroxy acids possessing aliphatic, aromatic and heteroaromatic moieties were isolated in high yield (67-85 %) and enantiopure form (>99 % ee) without requiring chromatographic purification.
