Weiss, Markus, Palmer, Joanne and Röhm, K H (1995) Thermostable aminoacylase from Bacillus stearothermophilus: significance of the metal center for catalysis and protein stability. Biological chemistry Hoppe-Seyler, 376 (11). pp. 643-649. ISSN 0177-3593

Abstract

A thermostable aminoacylase (N-acylamino acid amidohydrolase, EC 3.5.1.14) from Bacillus stearothermophilus was overexpressed in E. coli and characterized with respect to metal content, metal dependence, heat stability, and quaternary structure. Like other enzymes of the aminoacylase family, native aminoacylase contains one Zn2+ ion per subunit. Several other transition metal ions (Co2+, Mn2+ and Cd2+) also sustain aminoacylase activity toward N-acetyl L-alanine with Cd2+ giving the highest turnover number. The stability constants of the respective metal complexes were estimated by activity measurements in metal buffer systems. Co2+ also acts as an activator mainly by lowering the Km for the substrate. These data and CD spectra obtained with the native and the metal-free enzyme suggest a predominantly structural role for the intrinsic metal ion of thermostable aminoacylase. In contrast to previous reports the enzyme behaved as a dimer in analytical gel filtration.

Item Type:	Article
Date Deposited:	31 Jan 2012 00:45
Last Modified:	01 Feb 2013 00:46
URI:	https://oak.novartis.com/id/eprint/6181