Structural aspects of glucans formed in solution and on the surface of hydroxyapatite
Structural aspects of glucans formed in solution and on the surface of hydroxyapatite
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DOI：
10.1093/glycob/7.7.929
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发表时间：
1997-10-01
期刊：
影响因子：
4.3
通讯作者：
Bowen, WH
中科院分区：
文献类型：
--
作者：
Kopec, LK;VaccaSmith, AM;Bowen, WH
变形链球菌葡糖基转移酶类（GtfB、-C和-D）及其由蔗糖、葡聚糖形成的产物在龋病的发病机制中起重要作用。GtfB葡聚糖主要是1，3-连接的，其通过唾液（溶液）结合到体内牙齿上形成的唾液膜中（表面）;然而，来自GtfB表面形成的葡聚糖比在溶液中形成的葡聚糖含有更大量的3-连接葡萄糖。相比之下，在蔗糖和淀粉水解产物存在下由GtfB在表面上形成的葡聚糖的主要键是3-连接的葡萄糖，溶液中的GtfC衍生的葡聚糖具有6-连接的葡萄糖的主要键，而来自相同酶的表面形成的葡聚糖具有3-连接的葡萄糖作为主要键。在溶液中或表面上形成的GtfD葡聚糖主要是1，6-连接的;然而，表面形成的葡聚糖比溶液形成的葡聚糖含有更多的6-连接的葡萄糖。用葡聚糖水解酶变聚糖酶和葡聚糖酶消化显示，由每种Gtf酶在溶液中或在表面上形成的葡聚糖之间的敏感性不同，并且在来自这些二聚体的可溶性终产物中也观察到差异，我们的研究结果表明，相同的Gtf酶可以在溶液中和表面上形成结构不同的葡聚糖，这些观察结果在自然发生的微生物膜的研究中是重要的。
Streptococcus mutans glucosyltransferases (GtfB, -C, and -D) and their products formed from sucrose, glucans, play an essential role in the pathogenesis of dental caries, Enzymatically active Gtf is found in whole human saliva (solution), and incorporated into the salivary pellicle that is formed on teeth in vivo (surface), GtfB glucans are predominantly 1,3-linked; however, surface-formed glucans from GtfB contain greater amounts of 3-linked glucose than glucans formed in solution. In contrast, the major linkage of glucans formed on the surface by GtfB in the presence of sucrose and starch hydrolysates is 3-linked glucose, GtfC-derived glucans in solution have a major linkage of 6-linked glucose, while surface-formed glucans from the same enzyme have 3-linked glucose as the major linkage. GtfD glucans formed either in solution or on the surface are predominantly 1,6-linked; however, surface-formed glucans contain more 6-linked glucose than solution-formed glucans, Digestion with the glucanohydrolases mutanase and dextranase shows differences in susceptibility among glucans formed either in solution or on the surface by each of the Gtf enzymes, and differences are also seen in the soluble end products from these digestions, Our results show that the same Gtf enzyme can form structurally distinct glucans in solution and on a surface, These observations are important in the study of naturally occurring microbial films.