Site-directed mutagenesis of Asp280 suggests substrate-assisted catalysis of chitinase A1 from Bacillus circulans WL-12.
To study the involvement of Asp280 of chitinase A1 from Bacillus circulans WL-12 in the catalytic reaction of the enzyme, site-directed mutagenesis of this residue was carried out. Kinetic analysis of the mutant chitinases revealed that the residue is not absolutely essential for the catalytic reaction and thus, does not act as the catalytic nucleophile.
Hashimoto
M
M
Department of Biosystem Science, Graduate School of Science and Technology, Niigata University, 8050 Ikarashi-2, Niigata 950-2181, Japan.
Honda
Y
Y
Nikaidou
N
N
Fukamizo
T
T
Watanabe
T
T