桑寄生毒蛋白的分离纯化与部分性质研究

PURIFICATION AND CHARACTERIZATION OF A CYTOTOXIN FROM LORANTHAS PARASTTICUS MERR

中药桑寄生(Loranthas parasiticus Merr)中的毒蛋白(简称LPT)可以用DE—52离子交换层析和Sepbacryl—S—200分子筛过滤进行分离纯化.纯化的IPT进行还原及非还原SDS—PAGE,均呈现单一蛋白带且测得分子量为43,000d,表明LPT为一单链蛋白质.LPT对骨髓瘤细胞具有杀伤作用,其半致死量ID_(?)为1.O×10^(-7)mol/L.LPT对兔网织红细胞破碎中的蛋白质生物合成也具有抑作用,其半数抑制剂量为7.0×10^(-5)mo/L.

A cytotoxin from Loranthas parasiticus Merr (LPT) was isolated and purifiedby chromatography on DEAE-Cellulose and sephacryl S-200,and thus a single band was given on sodium doiecyl suiphatepolyacrylamide gel electrophoresis (SDS -PAGE) with or without 2 -meroaptoethenol LPT was proved to be a single chain protein with a molecular weight (MW)of a pproximately 43,000 dalton The experimental results showed LPT was toxic to myeloma cells with an ID50 of 1. 0 × 10-7mol/L, and could inhibit the protein eynthesis in a lysate of rabbit reticulocytes with an ID50 of 7.0 × 10-6mol/L.