College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, China.
Virology. 2011 Feb 20;410(2):299-306. doi: 10.1016/j.virol.2010.11.014. Epub 2010 Dec 21.
Porcine aminopeptidase N (pAPN) is a cellular receptor of transmissible gastroenteritis virus (TGEV), a porcine coronavirus. Interaction between the spike (S) protein of TGEV and pAPN initiates cell infection. Small molecules, especially peptides are an expanding area for therapy or diagnostic assays for viral diseases. Here, the peptides capable of binding the pAPN were, for the first time, identified by biopanning using a random 12-mer peptide library to the immobilized protein. Three chemically synthesized peptides recognizing the pAPN showed effective inhibition ability to TGEV infection in vitro. A putative TxxF motif was identified in the S protein of TGEV. Phages bearing the specific peptides interacted with the pAPN in ELISA. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays confirmed the protective effect of the peptides on cell infection by TGEV. Moreover, the excellent immune responses in mice induced by the identified phages provided the possibility to develop novel phage-based vaccines.
猪氨基肽酶 N（pAPN）是猪传染性胃肠炎病毒（TGEV）的细胞受体，TGEV 是一种猪冠状病毒。TGEV 的刺突（S）蛋白与 pAPN 之间的相互作用启动了细胞感染。小分子，特别是肽类，是治疗或诊断病毒疾病的新领域。在这里，首次通过生物淘选技术，使用固定化蛋白的随机 12 肽文库，鉴定出能够与 pAPN 结合的肽。三种化学合成的肽类能够识别 pAPN，对体外 TGEV 感染具有有效的抑制作用。在 TGEV 的 S 蛋白中鉴定出一个假定的 TxxF 基序。在 ELISA 中，携带特异性肽的噬菌体与 pAPN 相互作用。3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（MTT）测定法证实了这些肽对 TGEV 感染细胞的保护作用。此外，鉴定出的噬菌体在小鼠中诱导出的优异免疫反应为开发新型噬菌体疫苗提供了可能。
