Chemical and functional properties of mutastein, an inhibitor of insoluble glucan synthesis by Streptococcus sobrinus.

Abstract

Mutastein, a potent inhibitor of insoluble glucan synthesis by Streptococcus sobrinus, is a protein with a molecular weight of approximately 2 x 10(6). Amino acid and ELISA analyses suggested that mutastein is a mixture of heterogenous polymers of alpha-casein contained in the culture medium of the producing strain, Aspergillus terreus M3328. Mutastein strongly inhibited the primer-dependent insoluble glucan synthase of S. sobrinus B13. The primer-independent soluble glucan synthase was not affected by mutastein while primer-dependent soluble glucan synthase was slightly activated.