2fmj

From Proteopedia

Revision as of 18:00, 18 March 2008

220-loop mutant of streptomyces griseus trypsin

Overview

Serine proteases of the chymotrypsin family show a dichotomous amino acid distribution for residue 225. Enzymes carrying Tyr at position 225 are activated by Na(+), whereas those carrying Pro are devoid of Na(+) binding and activation. Previous studies have demonstrated that the Y225P conversion is sufficient to abrogate Na(+) activation in several enzymes. However, the reverse substitution P225Y is necessary but not sufficient to introduce Na(+) binding and activation. Here we report that Streptomyces griseus trypsin, carrying Pro-225, can be engineered into a Na(+)-activated enzyme by replacing residues in the 170, 186, and 220 loops to those of coagulation factor Xa. The findings represent the first instance of an engineered Na(+)-activated enzyme and a proof of principle that should enable the design of other proteases with enhanced catalytic activity and allosteric regulation mediated by monovalent cation binding.

About this Structure

2FMJ is a Single protein structure of sequence from Streptomyces griseus with and as ligands. Active as Trypsin, with EC number 3.4.21.4 Full crystallographic information is available from OCA.

Reference

Conversion of trypsin into a Na(+)-activated enzyme., Page MJ, Bleackley MR, Wong S, MacGillivray RT, Di Cera E, Biochemistry. 2006 Mar 7;45(9):2987-93. PMID:16503653

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