Substrate specificity in the highly heterogeneous M4 peptidase family is determined by a small subset of amino acids

Citation
A. De Kreij et al., Substrate specificity in the highly heterogeneous M4 peptidase family is determined by a small subset of amino acids, J BIOL CHEM, 275(40), 2000, pp. 31115-31120
Citations number
47
Categorie Soggetti
Biochemistry & Biophysics
Journal title
JOURNAL OF BIOLOGICAL CHEMISTRY
ISSN journal
00219258 → ACNP
Volume
275
Issue
40
Year of publication
2000
Pages
31115 - 31120
Database
ISI
SICI code
0021-9258(20001006)275:40<31115:SSITHH>2.0.ZU;2-F
Abstract
The members of the M4 peptidase family are involved in processes as diverse as pathogenicity and industrial applications. For the first time a number of M4 family members, also known as thermolysin-like proteases, has been ch aracterized with an identical substrate set and a uniform set of assay cond itions. Characterization with peptide substrates as well as high performanc e liquid chromatography analysis of p-casein digests shows that the M4 fami ly is a homogeneous family in terms of catalysis, even though there is a si gnificant degree of amino acid sequence variation. The results of this stud y show that differences in substrate specificity within the M4 family do no t correlate with overall sequence differences but depend on a small number of identifiable amino acids. Indeed, molecular modeling followed by site-di rected mutagenesis of one of the substrate binding pocket residues of the t hermolysin-like proteases of Bacillus stearothermophilus converted the cata lytic characteristics of this variant into that of thermolysin.