FIG. 4.
Detection of chitinolytic enzymes in extracellular proteins after separation by SDS-PAGE. Chitinolytic activity was detected with the substrates 4-MU- GlcNAc (A), 4-MU-(GlcNAc)2 (B), and 4-MU-(GlcNAc)3 (C). Lanes 1 and 2, extracellular proteins from strains CV026 and CV017 grown on SM with chitin; lane 3, extracellular proteins from strain CV026 grown on SM with chitin supplemented with HHL (10 μM); lane 4, extracellular proteins of strain CV017 boiled for 4 min in sample buffer containing 2-mercaptoethanol prior to loading. High-range prestained SDS-PAGE standards (Bio-Rad) were used as size markers (M). The positions of protein size markers are shown on the right.