Characterization of Metalloprotease from Vibrio mimicus and Determination of Substrate Binding Site

Characterization of Metalloprotease from Vibrio mimicus and Determination of Substrate Binding Site

Creators Jong-Hee Lee

Creators Sun-Hee Ahn

Creators In-Soo Kong

To investigate the enzymatic properties of Vibrio mimicus metalloprotease, the mature metalloprotease gene (vmc) was overexpressed in Escherichia coli and the recombinant protein (rVMC61) was purified by metal affinity chromatography. The rVMC61 showed maximum activity at about 37℃, pH 8. The purified rVMC61 was very specific toward collagen substrates, such as gelatin, type I. II, and III collagens and synthetic peptides (Cbz-GPLGP and Cbz-GPGGPA). To examine the role of the C-terminal region of rVMC61, the 3' end of the vmc gene was digested serially with exonuclease III. We demonstrate that deletion of 100 amino acids, but not 67 amino acids, from the C-terminus of the intact VMC protein (VMC61) abolished the collagenase activity. The intervening 33-amino acid region contains a repeated FAXWXXT motif that is essential for insoluble type I collagen binding. The isolated 33-amino acid peptide bound to insoluble type I collagen, while a peptide containing only the first FAXWXXT motif did not. Compared to the VMC61, the 33-amino acid peptide corresponding to the C-terminus exhibited a similar binding affinity and a lower binding capacity.

[ISSN]0370-9361