Biochemical and immunological relationships between endo-β1,4-glucanases from cockroaches

The cellulase from Geoscapheus dilatatus consisted of two major and four minor endo-beta-1,4-glucanase components. Two major and one minor component were purified to homogeneity. The major endo-beta-1,4-glucanase components, named GD1 and GD2, were similar to EG1 and EG2 from Panesthia cribrata in terms of M-r and kinetic properties. The purified minor component, named GD3, was distinct from GD1 and GD2 because of a lower M-r and a lower specific activity. Polyclonal antibodies raised against the two major endo-beta 1,4-glucanase components, EG1 and EG2, of the cellulase from P. cribrata cross-reacted with each other and with pure GD1 and GD2 from the foregut and midgut of the related cockroach G. dilatatus but did not crossreact with GD3. Endo-beta-1,4-glucanase components were partially purified from the foregut and midgut of four other cockroaches. These comprised three other Australian cockroaches also from the superfamily Blaberoidea and one American cockroach, Cryptocercus punctulatus, from the superfamily Blattoidea. The endogenous cellulases from all cockroaches examined consisted of either two or three major endo-pl,di-glucanase components. The amino acid sequence of the N-terminus region of the two major endo-beta-1,4-glucanase components from P. cribrata were determined and are homologous with those belonging to glycosyl hydrolase family 9 (cellulase family E). (C) 1997 Elsevier Science Inc.