Blusch Jürgen H, Seelmeir Sigrid, von der Helm Klaus
Max-von-Pettenkofer Institut, Ludwig-Maximilians-Universität München, D-80336 Munich, Germany.
J Virol. 2002 Aug;76(15):7913-7. doi: 10.1128/jvi.76.15.7913-7917.2002.
The protease of the porcine endogenous retrovirus (PERV) subtypes A/B and C was recombinantly expressed in Escherichia coli as proteolytically active enzyme and characterized. The PERV Gag precursor was also recombinantly produced and used as the substrate in an in vitro enzyme assay in parallel with synthetic nonapeptide substrates designed according to cleavage site sequences identified in the PERV Gag precursor. The proteases of all PERV subtypes consist of 127 amino acid residues with an M(r) of 14,000 as revealed by determining the protease N and C termini. The PERV proteases have a high specificity for PERV substrates and do not cleave human immunodeficiency virus (HIV)-specific substrates, nor are they inhibited by specific HIV protease inhibitors. Among the known retroviral proteases, the PERV proteases resemble most closely the protease of the murine leukemia retrovirus.
猪内源性逆转录病毒（PERV）A/B和C亚型的蛋白酶在大肠杆菌中重组表达为具有蛋白水解活性的酶并进行了特性鉴定。PERV Gag前体也进行了重组表达，并在体外酶测定中用作底物，同时还使用了根据在PERV Gag前体中鉴定的切割位点序列设计的合成九肽底物。通过测定蛋白酶的N端和C端发现，所有PERV亚型的蛋白酶均由127个氨基酸残基组成，分子量为14,000。PERV蛋白酶对PERV底物具有高度特异性，不会切割人类免疫缺陷病毒（HIV）特异性底物，也不会被特定的HIV蛋白酶抑制剂抑制。在已知的逆转录病毒蛋白酶中，PERV蛋白酶与鼠白血病逆转录病毒的蛋白酶最为相似。
