Lytic activity of Ts2631 endolysin variants.

Substitutions were generated by site-directed mutagenesis of a clone of Ts2631 endolysin in the pET15b vector (Novagen) using oligonucleotides with a degenerate sequence at the target codon. Mutations are identified by the one-letter code for the wild-type amino acid followed by the residue number and then the one-letter code for the mutant amino acid. Amidase activity was measured in a standard turbidity assay against chloroform-treated substrate T. thermophilus HB8. Activities are expressed as percentage in relation to the native Ts2631 endolysin control. Values represent the mean ± standard deviation (n = 3).