【摘要】 通过硫酸铵分级沉淀、CM 5 2阳离子交换层析、SephacrylS 10 0凝胶过滤和FPLCMono S离子交换层析等步骤 ,从栝楼种子中分离到一种核糖体失活蛋白———S trichokirin ,经 15 %SDS PAGE测定分子量为 8kD左右 ,13.5 %聚丙烯酰胺凝胶酸性电泳结果显示其等电点在 pH 9.5左右。通过对大鼠肝核糖体作用的研究 ,表明S tri chokirin属于RNAN 糖苷酶催化型的核糖体失活蛋白 ,对兔网织红细胞裂解液系统蛋白质生物合成有较强的抑制作用 ,IC50 为 1.15× 10 -10 mol/L。更多还原

【Abstract】 A new small ribosome-inactivating protein named S-trichokirin from the seeds of Trichosanthes kirilowii was purified by ammonia sulfate precipi tati on, CM-52 ion exchange chromatography, Sephacryl S-100 gel filtration and FPLC M ono S ion exchange chromatography. S-trichokirin has molecular weight about 8 k D , as determined by 15% SDS-PAGE and 15% Tris-Tricine PAGE. It was proved to be a strong basic protein with pI about pH 9.5 by 13.5% acidic PAGE. The reaction me chanism of S-trichokirin is the same as that of trichosanthin, which is an RNA N -glycosidase. It had a strong inhibitory effect on protein biosynthesis in rabb i t reticulocyte lysate with IC 50 of 1.15×10 -10 mol/L. S-trichokiri n may be used as a new efficient moiety of immunotoxin.更多还原