Trimeric l-N-carbamoylase from newly isolated Brevibacillus reuszeri HSN1: A potential biocatalyst for production of l-α-amino acids
Article first published online: 25 JAN 2013
© 2013 International Union of Biochemistry and Molecular Biology, Inc.
Biotechnology and Applied Biochemistry
Volume 60, Issue 2, pages 219–230, March/April 2013
How to Cite
Nandanwar, H. S., Vohra, R. M. and Hoondal, G. S. (2013), Trimeric l-N-carbamoylase from newly isolated Brevibacillus reuszeri HSN1: A potential biocatalyst for production of l-α-amino acids. Biotechnology and Applied Biochemistry, 60: 219–230. doi: 10.1002/bab.1066
- Issue published online: 18 APR 2013
- Article first published online: 25 JAN 2013
- Manuscript Accepted: 20 NOV 2012
- Manuscript Received: 17 SEP 2012
- Brevibacillus reuszeri;
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 µmol/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 µmol/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-α-amino acids. The enzyme activity was enhanced by 73% in the presence of 0.8 mM Mn2+ 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-α-amino acid production.