The property of major cellulases from the guts of Anoplophora glabripennis larvae have been characterized. The optimal temperatures of both β 1,4 glucosidase (β glucosidase) and endo β 1,4 endoglucanase (endoglucanase, Cx) are 40℃. The β glucosidase was optimally active at pH 4\^8, while the optimal activity of the endoglucanase occurred at pH 4 4 5 6 The endoglucanase was active with a wide range of pH and temperature, the levels of activity from 25℃ to 50℃ were more than 80%, and the activity remained 60% between pH 3 2 and pH 7 2. The endoglucanase exhibited higher thermal stability than β glucosidase. Both enzymes lose their activities by heat treatment at 60℃. Two isozymes of endoglucanase were detected in sodium carboxymethylcellulose polyacrymide gels (CMC gel) by chemical colorization, and purified by elution from the gel slices. The molecular weights of the two isozymes were estimated as 26kD and 39kD respectively. Moreover molecular characteristics of the two isozymes are currently underway.
Endoglucanases are the main cellulolytic enzymes digestion as well as its good kinetic properties make it an attractive of Anoplophora glabripennis. Their high activities in cellulose target for development of cellulase inhibitors. In this study, random pepfide phage display technology was employed to identify peptides that bound the AgEG1, a member of endoglucanase isozymes. Phage clones with peptide LPPNPTK and XPP （X is residue T, L, A or H） motif frequently occurred in the selected phage population and showed a higher phage recovery than other clones. Peptide LPPNPTK was chemically synthesized and characterized tor its binding activities to AgEG1. The synthetic peptide exhibited high specificity for AgEG1. The peptide LPPNPTK has the potential to be developed into inhibitors of the endoglucanase of A. glabripennis.
