%A Hemraj S Nandanwar
%A Rakesh M Vohra
%A Gurinder S Hoondal
%O Copyright of this article belongs to John Wiley & Sons.
%J Biotechnology and applied biochemistry
%T Trimeric l-N-carbamoylase from newly isolated Brevibacillus reuszeri HSN1: a potential biocatalyst for production of l-?-amino acids.
%X l-N-carbamoylase was isolated from Brevibacillus reuszeri HSN1 and purified to homogeneity in three steps, which is a reasonably short protocol for native l-N-carbamoylase. The enzyme purification protocol resulted in ?60-fold purification of l-N-carbamoylase with specific activity of 145 ?mol/Min/mg. The subunit and native molecular mass were found to be 44.3 and 132 kDa, respectively. Temperature and pH optima were determined as 50?C and 8.5, respectively. The enzyme had retained ?86% activity at 50?C when incubated for 60 Min and the half-life was determined as 180 Min at 50?C. N-carbamoyl-l-methionine (l-N-CMet) was found to be a preferred substrate with Km and Vmax values of ?13.5 mM and ?103 ?mol/Min/mg, respectively. The broad substrate specificity with derivatives of N-carbamoyl amino acids is advantageous to be a better biocatalyst for production of corresponding l-?-amino acids. The enzyme activity was enhanced by 73% in the presence of 0.8 mM Mn(2+) ion during the biotransformation. In the batch experiment, ?97% conversion of 5.0% l-N-CMet into enantiomerically pure l-methionine was achieved in 10 H when carried out at pH 8.0, 45?C, and 15% wet (w/v) cell loading, under controlled conditions. The overall merits of this enzyme show promise as a potential biocatalyst for l-?-amino acid production.
%N 2
%P 219-30
%V 60
%D 2013
%I John Wiley & Sons
%L open2422