IMPROVED PROCEDURES FOR PREPARATION AND CHARACTERIZATION OF MYROTHECIUM CELLULASE: PART 4. CHARACTERIZATION OF ACTIVITY TOWARD β-METHYL GLYCOSIDES OF 1 → 4-β-D-OLIGOGLUCOSIDES

Abstract

Two methods for the preparation of β-methyl glycosides of 1 → 4-β-D-oligoglucosides are described. In method I, the parent oligoglucoside is acetylated, acetobrominated, methylated, fractionated on Magnesol, and deacetylated. In method II, an acetolysate of cellulose is acetobrominated, methylated, deacetylated, and fractionated on Darco G60 charcoal.The parameters Km and k2 for the hydrolysis of β-methyl cellotetraoside by purified Myrothecium cellulase at pH 5.0 and 28.6° were estimated to be 4.1 × 10−4 M and 570 minute−1 respectively. Km decreases and k2 increases as the D.P. of the substrate is increased from three to five. The initial hydrolysis products of β-methyl cellotetraoside and β-methyl cellopentaoside indicate that the interior but not the terminal linkages are hydrolyzed by the enzyme.