FIG. 4.

GH18_N and GH18_C exhibit exo- and endochitinase activities, respectively. GH18_N and GH18_C were purified as described in Materials and Methods and incubated with GlcNAc₄ (A), GlcNAc₅ (B), and GlcNAc₆ (C). Standards and reaction products were labeled with 2-aminobenzoic acid and fractionated by electrophoresis in a 15% polyacrylamide gel (8). Labeled chitooligosaccharides were visualized by using a UV transilluminator. Standards, from bottom, are chitobiose, chitotriose, chitotetrose, and chitopentose.