Purification and characterization of Moschatin, a novel type Ⅰ ribosomeinactivating protein from the mature seeds of pumpkin (Cucurbita moschata), and preparation of its immunotoxin against human melanoma cells  

作　　者：HENG CHUAN XIA FENG LI ZHEN LI Zu CHUAN ZHANG 

机构地区：[1]Key Laboratory of Proteomics,Institute of Biochemistry and Cell Biology,Shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,Shanghai 200031,China.

出　　处：《Cell Research》2003年第5期369-374,共6页细胞研究(英文版)

摘　　要：A novel ribosome-inactivating protein designated Moschatin from the mature seeds of pumpkin (Cucurbita moschata) has been successively purified to homogeneity, using ammonium sulfate precipitation, CM-cellulose 52 column chromatography, Blue Sepharose CL-6B Affinity column chromatography and FPLC size-exclusion column chromatography. Moschatin is a type 1 RIP with a pI of 9.4 and molecular weight of~29 kD. It is a rRNA N-glycosidase and potently blocked the protein synthesis in the rabbit reticulocyte lysate with a IC_(50) of 0.26 nM. Using the anti-human melanoma McAb Ng76, a novel immunotoxin Moschatin-Ng76 was prepared successfully and it efficiently inhibited the growth of targeted melanoma cells M_(21) with a IC_(50) of 0.04 nM, 1500 times lower than that of free Moschatin. The results implied that Moschatin could be used as a new potential anticancer agent.

关 键 词：ribosome-inactivating protein (RIP) Moschatin immunotoxin. 

分 类 号：R73-3[医药卫生—肿瘤]