Anti-tumor activity and immunological modification of ribosome-inactivating protein (RIP) from Momordica charantia by covalent attachment of polyethylene glycol

作者：Li Mengen; Chen Yiwen; Liu Zhongyu; Shen Fubing; Bian Xiaoxiao; Meng Yanfa^*

来源：Acta Biochimica et Biophysica Sinica, 2009, 41(9): 792-799.

DOI：10.1093/abbs/gmp068

• apoptosis
• bitter melon seed
• PEGylation
• ribosome-inactivating protein

Ribosome-inactivating proteins (RIPs) are a family of enzymes that depurinate rRNA and inhibit protein biosynthesis. Here we report the purification, apoptosis-inducing activity, and polyethylene glycol (PEG) modification of RIP from the bitter melon seeds. The protein has a homogenous N-terminal sequence of N-Asp-Val-Ser-Phe-Arg. Moreover, the RIP displayed strong apoptosis-inducing activity and suppressed cancer cell growth. This might be attributed to the activation of caspases-3. To make it available for in vivo application, the immunogenicity of RIP was reduced by chemical modification with 20 kDa (mPEG)(2)-Lys-NHS. The inhibition activity of both PEGylated and non-PEGylated RIP against cancer cells was much stronger than against normal cells, and the antigenicity of PEGylated RIP was reduced significantly. Our results suggested that the PEGylated RIP might be potentially developed as anti-cancer drug.

• 出版日期2009-9
• 单位四川大学; 成都医学院