Synthesis Of L-amino Acids Research Articles

Some selected properties of the recombinant aminoacylase from Escherichia coli LGE 36

Background: Aminoacylase has seen extensive use in the synthesis of L-amino acids. L-amino acids are widely used in the food and medical industries, as well as in healthcare. The effect of metal ions and inhibitors on the enzyme activity of recombinant intracellular aminoacylase of Escherichia coli LGE 36 was studied. Acetyl-D,L-methionine and glycyl-L-methionine dipeptide were used as substrates. It has been shown that with the addition of Co2+ ions, the acylase activity of the recombinant enzyme towards N-acetyl-D,L-methionine increases 3 times. In the case of glycyl-L-methionine, the peptidase activity of the recombinant aminoacylase of Escherichia coli LGE 36 increases more than 40 times. A number of other metal ions studied do not stimulate the hydrolytic activity of the enzyme, moreover some of them even inhibit it. PCMB completely inactivates the recombinant aminoacylase, EDTA reduces enzyme activity by 85%. Objective: This study aims to investigate how metal ions and inhibitors affect the enzyme activity of recombinant intracellular aminoacylase Escherichia coli LGE 36. Methods: In this study, a recombinant strain-producer of aminoacylase derived from Escherichia coli LGE 36 was employed. Escherichia coli cells were cultured in M9 minimal medium supplemented at 37°C. To assess aminoacylase activity, assays were conducted at 37°C using a reaction mixture of 0.2 ml final volume comprising 100 mM Na, K-phosphate buffer at pH 7.0, 0.2 mM CoCI2, 40 mM N-acetyl-D, L-methionine, and the enzyme in the appropriate concentration. Acylase activity was quantified as the amount of enzyme catalyzing the formation of 1µmol of L-methionine within 1 minute at 37°C and pH 7.0. Results: Some characteristics of the recombinant intracellular aminoacylase from E. coli LGE 36 were determined. For investigating the impact of metallic ions and inhibitors, acetylmethionine and glycylmethionine were employed as the substrates. Conclusion: The present study and the choice of right strategies for functional food products allows optimizing the process for production of optically active amino acids using the recombinant enzyme to obtain food and feed additives. Keywords: ion, metals, inhibitors, acetylmethionine, glycylmethionine, recombinant aminoacylase from Escherichia coli, enzyme.

An improved method of synthesis of N -protected L-amino acids as their benzoxymethyl esters

An improved method for the synthesis of L-amino acids as their benzoxymethyl esters has been reported. All the synthesized compounds were characterized by 1H NMR, EI–MS and IR spectroscopic methods.

ケト酸よりＬ‐アミノ酸の酵素的合成

ケト酸よりＬ‐アミノ酸の酵素的合成

Studies on the Synthesis of L-Amino Acids

l-Homoserine was prepared by the reduction of l-aspartic acid β-methyl ester with sodium borohydride in water solution without any racemization. The yield of l-homoserine was about 25% of the theoretical amount, and no product other than l-homoserine, l-aspartic acid and l-aspartic acid β-methyl ester was present in the reaction mixture. The low yield of l-homoserine was ascribed to the hydrolysis of the ester.l-Azetidine-2-carboxylic acid could not be detected in the reaction mixture. In contrast with the reduction of l-glutamic acid γ-esters, the reduction of l-aspartic acid β-ester was not accompanied by the cyclization.