Cleavage specificity of coxsackievirus 3C proteinase for peptide substrate.

The substrate requirements of coxsackievirus 3C proteinase (3Cpro) were investigated on the C-terminal side of the scissile bond using C-terminal truncated peptides of the substrate peptide Ac-EALFQGPPV. Not only the Gln-Gly bond of Ac-EALFQG-NH2 but also the C-terminal amide group of Ac-EALFQ-NH2 was hydrolyzed by 3Cpro, suggesting that the essential residues for cleavage by coxsackievirus 3Cpro would exist within the N-terminal 5 residues.