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Updated: Jun 28, 2026

Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions
Published on: January 26, 2024
Leu254 residue and calcium ions as new structural determinants of carboxypeptidase T substrate specificity
A M Grishin1, V Kh Akparov, G G Chestukhina
1Institute of Genetics and Selection of Industrial Microorganisms, Moscow, 117545, Russia.
Abstract:
New determinants of Thermoactinomyces vulgaris carboxypeptidase T (CPT) substrate specificity--structural calcium ions and Leu254 residue--were found by means of steady-state kinetics and site-directed mutagenesis. The removal of calcium ions shifted the selectivity profile of hydrolysis of tripeptide substrates with C-terminal Leu, Glu, and Arg from 64/1.7/1 to 162/1.3/1. Substitution of the hydrophobic Leu254 in CPT for polar Asn did not change hydrolysis efficiency of substrates with C-terminal Leu and Arg, but resulted in more than 28-fold decrease in activity towards the substrate with C-terminal Glu. It is shown that the His68 residue is not a structural determinant of CPT specificity.
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