The primary structure of a 1,4‐β‐glucan cellobiohydrolase from the fungus Trichoderma reesei QM 9414

The sequence of the approx. 490 amino acid residues of the main 1,4‐β‐glucan cellobiohydrolase (CBH I) (EC 3.2.1.91) from culture filtrates of the fungus Trichoderma reesei QM 9414 has been established by automatic liquid phase Edman degradation. Peptides obtained by chemical and enzymatic cleavage of the reduced and S ‐carboxymethylated protein were isolated by a combination of gel filtration and high‐performance liquid chromatography. The amino‐terminus of the single polypeptide chain is blocked by a pyroglutamyl residue. Most of the neutral carbohydrate present in the glycoprotein is bound within a short region near the carboxyl‐terminus. Three attachment sites of glucosamine residues have also been established.