Modification of the degree of branching of a beta-(1,3)-glucan affects aggregation behavior and activity in an oxidative burst assay.

Scleroglucan is a β-(1,3)-glucan which is highly branched at the 6-position with a single glucose residue. Acid hydrolysis of a high molecular weight scleroglucan gave a medium molecular weight, freely soluble material. Linkage analysis by the partially methylated alditol acetate method showed that the solubilized material had 30% branching.

Mechanism of the orotidine 5'-monophosphate decarboxylase-catalyzed reaction: importance of residues in the orotate binding site.

The reaction catalyzed by orotidine 5'-monophosphate decarboxylase (OMPDC) is accompanied by exceptional values for rate enhancement (k(cat)/k(non) = 7.1 × 10(16)) and catalytic proficiency [(k(cat)/K(M))/k(non) = 4.8 × 10(22) M(-1)].