Separation of the cellulolytic system of Trichoderma viride‐reesei mutant using medium pressure liquid chromatography and characterization of a new exo‐cellobiohydrolase*

Abstract

Using a combination of rapid medium pressure ion exchange chromatography on the cation exchanger Spheron Phosphate‐1000 and the anion exchanger Spheron DEAE‐1000 a number of enzyme fractions of the cellulolytic system of a mutant of the imperfect fungus Trichoderma viride‐reesei were isolated from the cultivation medium. One of the fractions, which appeared homogeneous on poly‐acrylamide gel electrophoresis and sedimentation analysis, was prepared on a larger scale. It was a glycoprotein with 7% of neutral sugars, having a molecular weight 66 600 ± 3% and a sedimentation coefficient 4.2 S. Its amino acid composition was determined as well as the N‐terminal amino acid sequence: Glyαa˙Val˙Pro. Since the isolated enzyme hydrolyzed Avicel, filter paper and – to a small extent – carboxymethylcellulose with the main product cellobiose, it was identified as exo‐cellobiohydrolase.