An amine: hydroxyacetone aminotransferase from Moraxella lacunata WZ34 for alaninol synthesis

Abstract

An amine:hydroxyacetone aminotransferase from an isolated soil bacterium, Moraxella lacunata WZ34, was employed to synthesize alaninol in the presence of hydroxyacetone and isopropylamine in this study. The optimal carbon and nitrogen sources were glycerol and beef extract, respectively. A wide range of amino donor specificity was detected with the aminotransferase, which exhibited a relative high activity (9.83 U mL(-1)) in the presence of isopropylamine. The enzyme was the most active at pH 8.5, and showed relatively higher activity at alkaline than acidic pH. Maximum activity was achieved at 30 degrees C, and the enzyme had good thermal stability below 60 degrees C. Metal ions such as Mg(2+) had positive effect (132.6%) on the enzyme, and (aminooxy)acetic acid, a typical aminotransferase inhibitor, significantly inhibited its activity. The enzyme activity was enhanced by the addition of 0.05 mM pyridoxal-5'-phosphate (PLP).

Transaminase biocatalysis: optimization and application

“…KNK168 TA was until recently the only R-selective TA to be identified from experimental microorganism screening. Moreover, a number of microorganisms with substrate specificities corresponding to those of the screening culture including Bacillus megaterium SC6394, 38 Moraxella lacunata WZ34, 39 Pseudomonas fluorescens KNK08-18, 40 Alcaligenes denitrificans Y2k-2, 41 Mesorhizobium sp. LUK 42 and Pseudomonas sp.…”

Biocatalytic Routes to Optically Active Amines

“…[46] In the last decade, w-transaminases have been extensively studied and they have been identified in a mere dozen organism. [47][48][49][50][51][52][53][54][55] They were biochemically characterized and also overexpressed in microbial hosts such as E. coli with the enzyme from Vibrio fluvialis as probably the most intensively studied w-transaminase. Most w-TAs exhibit (S)-selectivity, but a few examples of (R)-selective enzymes are known.…”

High-Yield Biocatalytic Amination Reactions in Organic Synthesis

“…This will facilitate the coupling of new transaminase activity discovery [117,118,119] with the investigations on the enzyme enantioselectivity as well as the optimization of reaction conditions to overcome thermodynamic barriers.…”