重组A群链球菌三磷酸甘油醛脱氢酶与脂蛋白(a)的相互作用  

THE INTERACTION BETWEEN LIPOPROTEIN(A) AN RECOMBINANT GLYCERALDEHYDE-3-PHOSPHATE DEHUDROGENASE DERIVED FROM GROUP A STREPTOCOCCUS

作　　者：代霄燕[1,2,3] 许丽萍[1,2,3] 白文成[1,2,3] 韩润林[1,2,3] 

机构地区：[1]内蒙古农业大学兽医学院,呼和浩特010019 [2]血浆脂蛋白免疫学研究中心 [3]兽用疫苗国家工程实验室工艺技术研究室,呼和浩特010018

出　　处：《内蒙古农业大学学报（自然科学版）》2011年第3期27-31,共5页Journal of Inner Mongolia Agricultural University(Natural Science Edition)

基　　金：国家自然科学基金(30860019)资助

摘　　要：三磷酸甘油醛脱氢酶(GAPDH)是A群链球菌(group A Streptococcus,GAS)表面的纤溶酶原(Plg)受体之一,其C末端的赖氨酸残基可以与Plg的赖氨酸结合位点(LBS)相结合。脂蛋白(a)[Lp(a)]中的载脂蛋白(a)[Apo(a)]与Plg有很高的同源性。因此本实验室提出了Lp(a)可能与GAS表面的Plg受体相结合,进而可能竞争性抑制GAS与Plg结合的假说。本研究克隆了GAS的GAPDH及其C末端敲除赖氨酸残基的突变体基因,酶切后将其连接到表达载体pASK-IBA37中,并在大肠杆菌BL-21中表达了这两个重组蛋白(rGAPDH和rGAPDHΔ345)。通过酶联免疫吸附试验(ELISA)对rGAPDH和rGAPDHΔ345与Lp(a)的相互作用机制进行了研究。结果表明rGAPDHΔ345与Lp(a)的结合值比rGAPDH显著降低,说明rGAPDH及rGAPDHΔ345与Lp(a)通过LBS发生特异性结合,而且一定浓度的赖氨酸类似物6-氨基己酸(EACA)可以抑制这种结合,Lp(a)对rGAPDH与Plg的相互作用也有明显的抑制。glyceraldehyde-3-phosphate dehydrogenase（GAPDH） is one of plasminogen（Plg） receptors on the surface of group A streptococcus（GAS）.Plg through its lysine binding sites（LBS） binds to GAPDH.Apolipoprotein（a） 、[Apo（a）],which is one component of Lipoprotein（a） ,has a high homology with Plg.Therefore,we previously postulated that Lp（a） might bind to Plg receptor on the surface of GAS,subsequently competitively inhibiting the interaction between GAS and Plg.To test our hypothesis,the GAPDH gene and its C-terminal lysine residues-truncated fragment of GAS was cloned into pASK-IBA37 respectively,and the recombinant GAPDH and rGAPDHΔ345（rGAPDH and rGAPDHΔ345） were expressed in E.coli BL21.The interaction between rGAPDH or rGAPDHΔ345 and Lp（a） was investigated by enzyme-linked immunosorbent assay（ELISA）.The results indicated that the binding of rGAPDHΔ345 to Lp（a） is significantly lower than that of rGAPDH.It can be suggest that Lp（a） via its LBS in Apo（a） bound to rGAPDH and rGAPDHΔ345 since EACA,a lysine analog,dramatically inhibited the binding.In addition,Lp（a） could partially inhibit the interaction between rGAPDH and Plg.

关 键 词：三磷酸甘油醛脱氢酶 A群链球菌 纤溶酶原 脂蛋白(a) 赖氨酸结合位点 

分 类 号：R914[医药卫生—药物化学]