1460-34-0Relevant articles and documents
Servis,R.E. et al.
, p. 5619 - 5624 (1969)
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)
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.
Asymmetric C-Alkylation by the S-Adenosylmethionine-Dependent Methyltransferase SgvM
Sommer-Kamann, Christina,Fries, Alexander,Mordhorst, Silja,Andexer, Jennifer N.,Müller, Michael
, p. 4033 - 4036 (2017)
S-Adenosylmethionine-dependent methyltransferases (MTs) play a decisive role in the biosynthesis of natural products and in epigenetic processes. MTs catalyze the methylation of heteroatoms and even of carbon atoms, which, in many cases, is a challenging reaction in conventional synthesis. However, C-MTs are often highly substrate-specific. Herein, we show that SgvM from Streptomyces griseoviridis features an extended substrate scope with respect to the nucleophile as well as the electrophile. Aside from its physiological substrate 4-methyl-2-oxovalerate, SgvM catalyzes the (di)methylation of pyruvate, 2-oxobutyrate, 2-oxovalerate, and phenylpyruvate at the β-carbon atom. Chiral-phase HPLC analysis revealed that the methylation of 2-oxovalerate occurs with R selectivity while the ethylation of 2-oxobutyrate with S-adenosylethionine results in the S enantiomer of 3-methyl-2-oxovalerate. Thus SgvM could be a valuable tool for asymmetric biocatalytic C-alkylation reactions.
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Ogawara et al.
, p. 3296,3298 (1968)
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Biocatalytic Construction of Quaternary Centers by Aldol Addition of 3,3-Disubstituted 2-Oxoacid Derivatives to Aldehydes
Marín-Valls, Roser,Hernández, Karel,Bolte, Michael,Parella, Teodor,Joglar, Jesús,Bujons, Jordi,Clapés, Pere
supporting information, p. 19754 - 19762 (2020/12/01)
The congested nature of quaternary carbons hinders their preparation, most notably when stereocontrol is required. Here we report a biocatalytic method for the creation of quaternary carbon centers with broad substrate scope, leading to different compound classes bearing this structural feature. The key step comprises the aldol addition of 3,3-disubstituted 2-oxoacids to aldehydes catalyzed by metal dependent 3-methyl-2-oxobutanoate hydroxymethyltransferase from E. coli (KPHMT) and variants thereof. The 3,3,3-trisubstituted 2-oxoacids thus produced were converted into 2-oxolactones and 3-hydroxy acids and directly to ulosonic acid derivatives, all bearing gem-dialkyl, gem-cycloalkyl, and spirocyclic quaternary centers. In addition, some of these reactions use a single enantiomer from racemic nucleophiles to afford stereopure quaternary carbons. The notable substrate tolerance and stereocontrol of these enzymes are indicative of their potential for the synthesis of structurally intricate molecules.