IdeE, an IgG-endopeptidase of Streptococcus equi ssp equi
IdeE, an IgG-endopeptidase of Streptococcus equi ssp equi
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DOI：
10.1111/j.1574-6968.2006.00404.x
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发表时间：
2006-09-01
影响因子：
2.1
通讯作者：
Guss, Bengt
中科院分区：
文献类型：
--
作者：
Lannergard, Jonas;Guss, Bengt
马链球菌。马是一种高度传染性和严重的马上呼吸道疾病--勒死病的病原体。本研究描述了化脓性链球菌分泌的免疫球蛋白G特异性蛋白水解酶IDES/Mac的同源基因IDEA的特征。将IdeE的活性与IdeZ的活性进行了比较，IdeZ是与马链霉菌紧密相关的SSP的相应酶。动物疫病。对重组IDEA和IDEZ对部分哺乳动物的免疫球蛋白的降解活性的研究表明，只有含有IDES/Mac底物位点的抗体被切割，表明这两种酶的特异性是相似的。有趣的是，马的免疫球蛋白没有狗或人的免疫球蛋白有效切割，因为马血清中的主要免疫球蛋白亚型(IgG4)缺乏一个明显的IDEA/IDEZ底物位点。在马链霉菌SSP中观察到免疫球蛋白降解。Equi在马血清存在的情况下生长，但不能在纯化的免疫球蛋白存在时生长。由于部分降解的IgG含有IgG4，因此观察到的活性可能是由于一种未知的酶的表达，而不是IDEA。在类似的实验中，在马链霉菌的生长培养液中没有检测到免疫球蛋白G的蛋白分解。动物疫病。
Streptococcus equi ssp. equi is the causative agent of strangles, a highly contagious and serious disease in the upper respiratory tract of horses. The present study describes the characterization of IdeE, a homolog of the secreted IgG-specific protease IdeS/Mac of Streptococcus pyogenes. The activity of IdeE is compared with the activity of IdeZ, the corresponding enzyme of the closely related S. equi ssp. zooepidemicus. A study of the proteolytic activity of recombinant IdeE and IdeZ on IgG from a selection of mammals shows that only antibodies containing the substrate site of IdeS/Mac are cleaved, indicating that the specificities of these enzymes are similar. Interestingly, IgG from horse is less effectively cleaved than IgG from e.g. dog or humans, as the dominating IgG isotype in horse sera (IgG4) lacks a distinct substrate site for IdeE/IdeZ. IgG-degradation is observed when S. equi ssp. equi is grown in the presence of horse serum, but not when grown with purified IgG. As the fraction of degraded IgG contains IgG4, the observed activity might be due to the expression of an unknown enzyme rather than IdeE. In a similar assay, no proteolysis of IgG was detected in the growth media of S. equi ssp. zooepidemicus.