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首页> 外文期刊>Infection and immunity >Interactions of antisera, sera, and oral fluid with glucosyltransferases.
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Interactions of antisera, sera, and oral fluid with glucosyltransferases.

机译：抗血清，血清和口腔液与葡萄糖基转移酶的相互作用。

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Partially purified glucosyltransferases (GTF) isolated from Streptococcus mutans OMZ 176 and respective rabbit antisera were used to study enzyme-antibody interactions. A comparison between sensitive serological techniques and a functional inhibition test based on a radioenzyme assay demonstrated that the latter test system was the only one that discriminated between different antisera. Positive reactions in high dilutions in the former test systems were explained by the involvement of non-GTF contaminants and/or antibodies against enzyme regions distant to the catalytic site. The minute cross-reactions between two enzyme fractions and the respective antisera in the functional inhibition test indicated that the two immunogens contained mainly GTF that differed in the structure of their catalytic region. Control rabbit sera, rat oral fluid, and insoluble and soluble glucans considerably activated the GTF eluted with a 0.5 M phosphate buffer from hydroxapatite. It is suggested that these enzymes had additional binding sites for macromolecules inherent to rabbit sera and rat oral fluid, respectively, and that the observed increase in enzyme activity was due to a more stable enzyme conformation. Possibly the stimulation of GTF by the soluble glucan fraction was caused by a primer and/or acceptor function; however, this was not the case of the insoluble glucan. A stable complex was formed in the absence of the enzyme substrate, sucrose, the activity of which was not readily enhanced. It is concluded that the GTF of strain OMZ 176 are composed of multiple, multi-reactive molecules that enable these enzymes to act as cross-linking agents.
机译：从变形链球菌OMZ 176和各自的兔抗血清中分离出的部分纯化的葡萄糖基转移酶（GTF）用于研究酶与抗体的相互作用。敏感的血清学技术与基于放射酶测定的功能抑制测试之间的比较表明，后者测试系统是唯一可区分不同抗血清的系统。在以前的测试系统中，高稀释度的阳性反应是由非GTF污染物和/或针对远离催化位点的酶区域的抗体引起的。在功能抑制试验中，两个酶馏分与各自的抗血清之间的微小交叉反应表明，这两个免疫原主要含有GTF，其催化区域的结构有所不同。对照兔血清，大鼠口腔液以及不溶和可溶的葡聚糖极大地激活了用0.5M磷灰石中的磷酸盐缓冲液洗脱的GTF。提示这些酶分别具有兔血清和大鼠口腔液固有的大分子的附加结合位点，并且观察到的酶活性增加是由于更稳定的酶构象。可能是可溶性葡聚糖组分对GTF的刺激是由引物和/或受体功能引起的。但是，不溶性葡聚糖不是这种情况。在不存在酶底物蔗糖的情况下形成稳定的复合物，其活性不易提高。结论是，菌株OMZ 176的GTF由多个多重反应性分子组成，这些分子可使这些酶充当交联剂。

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