926-61-4Relevant articles and documents
Degradation of pyrimidines in Saccharomyces kluyveri: Transamination of β-alanine
Schnackerz,Andersen,Dobritzsch,Piskur
, p. 794 - 799 (2008)
Beta-alanine is an intermediate in the reductive degradation of uracil. Recently we have identified and characterized the Saccharomyces kluyveri PYD4 gene and the corresponding enzyme β-alanine aminotransferase (SkPyd4p), highly homologous to eukaryotic γ-aminobutyrate aminotransferase (GABA-AT). S. kluyveri has two aminotransferases, GABA aminotransferase (SkUga1p) with 80% and SkPyd4p with 55% identity to S. cerevisiae GABA-AT. SkPyd4p is a typical pyridoxal phosphate-dependent aminotransferase, specific for α-ketoglutarate (αKG), β-alanine (BAL) and γ-aminobutyrate (GABA), showing a ping-pong kinetic mechanism involving two half-reactions and substrate inhibition. SkUga1p accepts only αKG and GABA but not BAL, thus only SkPydy4p belongs to the uracil degradative pathway. Copyright Taylor & Francis Group, LLC.
Kinetics and Mechanism of Electron Transfer Reactions in Aqueous Solutions: Silver(I) Catalyzed Oxidation of Aspartic Acid by Cerium(IV) in Acid Perchlorate Medium
Sharma, Indu,Devra, Vijai,Gupta, Divya,Gangwal, C. M.,Sharma, P. D.
, p. 311 - 320 (1995)
Silver(I) catalyzed oxidation of aspartic acid by cerium(IV) was studied in acid perchlorate medium.The stoichiometry of the reaction is represented by the eq. (i), (i) R-CHNH3+COOH + 2 Ce(IV) -H2O-> R-CHO + NH4+ + CO2 + 2 Ce(III) + 2 H+.Dimeric cerium(IV) species has been indicated and employed in calculations of monomeric cerium(IV) species concentrations.The reaction is second-order and uncatalyzed reaction also simultaneously occurs along with silver(I) catalyzed reaction conforming to the rate law (ii), (ii) , where k is an observed second-order rate constant.A probable reaction mechanism is suggested.
Soni,Menghani
, p. 5567 (1972)
Alkaline degradation of sulbactam
Haginaka,Wakai,Yasuda,et al.
, p. 2035 - 2043 (1985)
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Kinetic and mechanistic studies on the oxidation of DL-aspartic acid with manganese(III) in sulphuric acid medium
Makena, Rama Rajeswari,Rambabu, Rallabandi,Vani, Parvataneni
, p. 1073 - 1078 (2020/06/26)
The kinetics of oxidation of DL-aspartic acid by manganese(III) was studied spectrophotometrically at 500 nm in sulphuric acid medium at 40oC. The reaction was observed to be fractional order with respect to substrate and first order with respect to oxidant. Further the rate of reaction found to decrease with increase in ionic strength and [H+], while [HSO4-] and [MnII] were found to have negligible effect. The energy of activation, Ea and the entropy of activation, ΔS# computed from thermal studies were found to be 102.23±11.1 KJ mol-1 and 18.45±35.40 JK-1 mol-1 respectively.
Substrate profile of an ω-transaminase from Burkholderia vietnamiensis and its potential for the production of optically pure amines and unnatural amino acids
Jiang, Jinju,Chen, Xi,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
, p. 32 - 39 (2014/01/06)
A new (S)-enantioselective ω-transaminase (ω-TA) gene from Burkholderia vietnamiensis G4 was functionally expressed in Escherichia coli BL21 (DE3), and the purified recombinant N-terminal His-tagged ω-TA (HBV-ω-TA) had a dimeric structure with optimum pH and temperature of 8.4 and 40 C, respectively. The enzyme showed higher activities toward aromatic amines than aliphatic amines and (S)-1-methylbenzylamine ((S)-α-MBA) was the most active amino donor. For amino acceptor, keto acids, keto esters and aldehydes were more reactive than ketones with pyruvate ethyl ester being most active. Several chiral amines and unnatural amino acids or esters were synthesized using HBV-ω-TA as the catalyst and isopropylamine or (S)-α-MBA as amino donor. Notably, HBV-ω-TA catalyzed the amino transfer to β-keto esters to give optically pure β-amino acid esters. In addition, glyoxylate was used as amino acceptor for the first time in the kinetic resolution of racemic amines and optically pure amines, such as (R)-1-methylbenzylamine, (R)-1-phenylpropylamine, (R)-2-amino-4-phenylbutane and (R)-1-aminotetraline, were obtained.
