人脂蛋白(a)与金黄色葡萄球菌重组α-烯醇化酶的相互作用  

THE INTERACTION BETWEEN HUMAN LIPOPROTEIN(a) AND RECOMBINANT α-ENOLASE DERIVED FROM Staphylococcus aureus

作　　者：纪智星 白文成[2] 

机构地区：[1]内蒙古乌兰察布市集宁一中,集宁市012000 [2]内蒙古农业大学血浆脂蛋白免疫学研究中心,呼和浩特010018

出　　处：《内蒙古农业大学学报（自然科学版）》2017年第2期1-6,共6页Journal of Inner Mongolia Agricultural University(Natural Science Edition)

基　　金：国家自然科学基金(30860019)

摘　　要：表面α-烯醇化酶(Eno)是金黄色葡萄球菌(S.aureus)重要纤溶酶原受体(Plr),其C端Lys残基是与纤溶酶原(Plg)Kringle结构域(K或K结构域)结合位点之一。人脂蛋白(a)(Lp(a))是由一分子载脂蛋白(a)(apo(a))和一分子低密度脂蛋白(LDL)通过二硫键结合构成,apo(a)上的K结构域与Plg的K结构域具有高度同源性,都有赖氨酸结合位点(LBS)。Apo(a)的KIV_(10)是主要的LBS。因此假设,Lp(a)也可能与Eno结合,从而竞争性抑制Eno与Plg的结合。本文为研究Lp(a)与Eno的相互作用机制,在大肠杆菌中重组表达了Eno(rEno)及敲除C末端Lys残基(第434个氨基酸残基)的Eno(rEno△434)和apo(a)的KIV_(10)结构域(rKIV_(10));用酶联免疫吸附试验(ELISA)和亲和色谱层析(Pull down)对rEno、rEno△434与Plg、Lp(a)、LDL、rKIV_(10)的相互作用机制进行了研究。结果表明,rEno与Plg、Lp(a)、rKIV_(10)呈特异性结合,一定浓度的赖氨酸类似物6-氨基己酸(EACA)能够抑制它们的结合,证明Lp(a)与rEno也是通过LBS结合;rEno不与LDL结合,证明Lp(a)是通过apo(a)与rEno结合;rEno△434与Plg和Lp(a)的结合有明显降低,证明rEno的C端Lys残基是与Lp(a)结合的位点之一。α - Enolase（Eno）is one of important plasminogen（Plg） receptors on the surface of Staphylococcus aureas（S, aureus）. Plg can bind to C -terminal lysine residues of the Eno. Lipoprotein（a） [Lp（a）] contains an apoliporotein（a） [apo（a）] and a LDL. Apo （a） and Plg share a high similarity and both of them contain Kringle domains which contain lysine - binding sites （LBS）, one of strong LBS is KIV10 in apo（a）. Therefore, Lp（a） may bind to α -enolase on the surface ofS. aureus. In the paper, we investigated the interaction of recombinant α -enolase （rEno ） with Lp （ a ） and recombinant KIVIo （ rKIVlo ）. rEno, the recombinant α -enolase mutant with a deletion of C -terminal Lys434 （rEnoA434） and rKIVlowere expressed in E. coli. The bindings of rEno, rEno△434 to Pig, Lp （a）, LDL and rKIVt0 were detected by enzyme -linked immunosorbent assay （ELISA） and affinity chromatography fol- lowed with Western blot analysis. The result showed that rEno, rEno△434 could specifically bind to Pig, Lp（a）, rKIV10but not to LDL. Moreover, EACA could inhibit their bindings. The binding of rEno to Plg, Lp（a） is stronger than that of rEno△434. Our find- ings suggested that Lp（a） via its LBS bound to rEno and rEno△434, and the C -terminal lysine residue of rEno was one of the bind- ing site.

关 键 词：金黄色葡萄球菌 α-烯醇化酶 纤溶酶原 脂蛋白(a) 相互作用 

分 类 号：Q936[生物学—微生物学]