HEAT-RESISTANT CREATINE AMIDINOHYDROLASE AND ITS PRODUCTION

摘要

PROBLEM TO BE SOLVED: To obtain the subject new heat-resistant enzyme having such catalytic activity as to hydrolyze creatine to form sarcosine and urea, therefore to be used for determining the creatine levels in human body fluids and useful as e.g. a diagnostic for various diseases including nephropathy. ;SOLUTION: This enzyme, a new heat-resistant creatine amidinohydrolase, has the following physicochemical characteristics: having such a catalytic activity as to hydrolyze 1 mol creatine to form 1 mol sarcosine and 1 mol urea; having substrate specificity to creatine, an optimum pH of 7.0-8.0, a stable pH range of 4.0-11.0, and a suitable action temperature of about 45°C; stable at 53°C; having a molecular weight of 92,000 (gel filtration method). Being capable of determining the creatine levels in human serum or urine, this enzyme is useful as e.g. a diagnostic for various diseases including nephropathy. This new enzyme is obtained by integrating Escherichia coli with a recombinant plasmid containing Alcaligenes sp. KS-85 strain-derived creatine amidinohydrolase gene which is then expressed.;COPYRIGHT: (C)2000,JPO