Inhibitory effect of oleate on glucan synthesis of Streptococcus mutans

Abstract

Effects of oleate on glucan synthesis were examined by using crude enzymes, purified dextransucrase and partially purified mutansucrase from Streptococcus mutans HS-6.When crude enzymes were used, the oleate inhibited the water-insoluble glucan synthesis and simultaneously accelerated the water-soluble glucan synthesis. Although formation of water-soluble glucan by purified dextransucrase increased through an oleate concentration of 0.2 mM, it decreased at a higher concentration (65% inhibition at 1.0 mM). Synthesis of water-insoluble glucan by partially purified mutansucrase was inhibited by the oleate. These results are discussed in terms of the mechanism of glucan synthesis on crude enzymes in the presence of oleate.