Effect of seven inhibitors on invertases in homogenates of human dental plaque.

Seven known alpha-glucosidase/beta-fructosidase inhibitors were examined for inhibitory effect against invertases in pooled human dental plaque. The inhibitors used were acarbose, Trestatin, nojirimycin, 1-deoxynojirimycin, glucono-delta-lactam, conduritol-B-epoxide, and Hoe 467A. Plaque homogenates were incubated with 14C-labelled sucrose and invertase activity was assayed by determination of radio-labelled monosaccharide after paper chromatography. Conduritol-B-epoxide, acarbose, and Trestatin reduced the invertase activity an average of 62%, 51%, and 35% respectively. The other inhibitors affected the enzyme activity negligibly. By combining conduritol-B-epoxide with acarbose or Trestatin in other plaque homogenates the inhibition of invertases increased from 35% to 61%. This observation supported the concept that the invertases in dental plaque consist of both alpha-glucosidases and beta-fructosidases.