Vacca-Smith A M, Venkitaraman A R, Quivey R G, Bowen W H
Department of Dental Research, Rochester Caries Research Center, University of Rochester, NY 14642, USA.
Arch Oral Biol. 1996 Mar;41(3):291-8. doi: 10.1016/0003-9969(95)00129-8.
The salivary pellicle consists of various proteins and glycoproteins which may interact with one another. Experiments were performed to elucidate the interactions of streptococcal glucosyltransferase (Gtf) enzymes with human salivary alpha-amylase in solution and on the surface of saliva-coated hydroxyapatite (SHA) beads. The Gtf enzymes -B, -C and -D, when immobilized on to SHA beads, reduced the activity of adsorbed amylase; GtfD showed the highest inhibition of salivary amylase activity. The presence of glucan produced by immobilized GtfD did not further reduce amylase activity. The amount of amylase adsorbed on to hydroxyapatite beads was reduced when salivary amylase was added simultaneously with any of the Gtf enzymes, suggesting that amylase and Gtfs may compete with each other for binding sites on hydroxyapatite. Starch hydrolysates produced by SHA-surface-bound salivary amylase were tested for their effect on glucan production from sucrose by Gtf enzymes in solution and on SHA beads; glucan production by SHA-immobilized GtfB was stimulated in the presence of starch hydrolysates. Glucan synthesized by SHA-immobilized GtfB in the presence of starch hydrolysates was less susceptible to hydrolysis by the fungal enzyme mutanase than was glucan made by SHA-immobilized GtfB in the absence of starch hydrolysates. Glucan production by GtfB associated with streptococci immobilized on to SHA was also enhanced in the presence of starch hydrolysates. The adhesion of oral micro-organisms to SHA coated with glucan made in the presence and absence of starch hydrolysates was investigated, and some bacteria displayed higher adhesion activities for the glucan made in the presence of the hydrolysates. Therefore, the interaction of amylase and Gtf enzymes on a SHA surface may modulate the formation of glucan and the adherence of oral micro-organisms.
唾液薄膜由多种可能相互作用的蛋白质和糖蛋白组成。进行了实验以阐明链球菌葡糖基转移酶（Gtf）酶与溶液中和唾液包被的羟基磷灰石（SHA）珠表面上的人唾液α-淀粉酶之间的相互作用。当Gtf酶-B、-C和-D固定在SHA珠上时，会降低吸附的淀粉酶的活性；GtfD对唾液淀粉酶活性的抑制作用最强。固定化GtfD产生的葡聚糖的存在并未进一步降低淀粉酶活性。当唾液淀粉酶与任何一种Gtf酶同时添加时，吸附在羟基磷灰石珠上的淀粉酶量会减少，这表明淀粉酶和Gtfs可能会相互竞争羟基磷灰石上的结合位点。测试了SHA表面结合的唾液淀粉酶产生的淀粉水解产物对溶液中和SHA珠上Gtf酶从蔗糖产生葡聚糖的影响；在淀粉水解产物存在的情况下，固定在SHA上的GtfB的葡聚糖产生受到刺激。与在不存在淀粉水解产物的情况下由固定在SHA上的GtfB产生的葡聚糖相比，在淀粉水解产物存在的情况下由固定在SHA上的GtfB合成的葡聚糖对真菌酶变聚糖酶的水解更不敏感。在淀粉水解产物存在的情况下，固定在SHA上的与链球菌相关的GtfB的葡聚糖产生也会增强。研究了口腔微生物对在存在和不存在淀粉水解产物的情况下制成的葡聚糖包被的SHA的粘附情况，一些细菌对在水解产物存在的情况下制成的葡聚糖表现出更高的粘附活性。因此，淀粉酶和Gtf酶在SHA表面上的相互作用可能会调节葡聚糖的形成和口腔微生物的粘附。
