血型链球菌和变形链球菌葡糖基转移酶的对比分析

A comparative analysis of biological properties of glucosyltranterases secreted hy Streptococcus sanguis and Streptococcus mutans

通过对血型链球菌（以下简称血链菌）３４和变形链球菌（以下简称变链菌）Ｉｎｇｂｒｉｔｔ（ｃ）葡糖基转移酶（ＧＴＦ）的活性测定，以及合成胞外多糖的对比分析，得出以下结论：（１）在相同培养条件下，提取血链菌３４的胞外ＧＴＦ的酶蛋白量比变链菌Ｉｎｇｂｒｉｔｔ（ｃ）多，而变链菌Ｉｎｇｂｒｉｔｔ（ｃ）胞外ＧＴＦ的酶活性高于血链菌３４；（２）血链菌３４的胞外ＧＴＦ酶具有合成ＩＧ和ＳＧ的能力，与变链菌Ｉｎｇｂｒｉｔｔ（ｃ）的胞外ＧＴＦ酶一样具有多形性，血链菌可以催化形成足够的葡聚糖来激活变链菌引物依赖型的ＧＴＦ酶，对牙菌斑的后继定殖菌是非常有利的；（３）获取血链菌３４的ＧＴＦ纯酶制剂比变链菌Ｉｎｇｂｒｉｔｔ（ｃ）容易。

Abstract Our study make a comparative anlysis of biological properties of glucosyltranterases(GTF)secreted by S.sanguis 34 and S. mutans ingbritt(c).The results as follows:1)S.sanguis 34 has more extractions of extracelluarGTF than S.mutans Ingbritt(c)under equal cultured conditions,but S.mutans ingbritt(c) has more activity of extracelluar GTF than S. sanguis.These differences are identical with the differences of their cariogenicities;2)GTF of S. sanguis 34 can also synthesize water-insoluble glucan and water-soluble glucan,and is a multienzyme complex system as S.mutans.S.sanguis mights catalyse sufficient dextran formation to stimulate the primer-dependent activity of the S.mutans GTF enzyme.This might aid the adhesion of this comparatively late colonizer;3)easier to abstract hight pured GTF of S. sanguis 34 than S. mutans.