摘要
从香樟树成熟的种子分离到两种新的Ⅱ型核糖体失活蛋白 :新丰毒蛋白和辛纳毒蛋白 .两者A链的分子质量虽然相差近一倍 ,但B链的分子质量相同 .Ⅱ型核糖体失活蛋白的A链是RNAN 糖苷酶 ,B链是凝集素 ,A链进入细胞表现毒性在很大程度上依赖于B链的糖结合活性和特异性 .对辛纳毒蛋白和新丰毒蛋白B链的凝集素活性进行了测定和比较 .红细胞凝集实验显示辛纳毒蛋白和新丰毒蛋白具有相同的细胞凝集活性 ,半抗原抑制实验发现它们都属于半乳糖型核糖体失活蛋白 ,荧光光谱法显示它们的糖结合常数也相同 .
Two new type Ⅱ ribosome-inactivating proteins (RIPs) were isolated from the mature seed of camphor tree (Cinnamomum camphora). They are named cinnamomin and cinphorin. The molecular mass of cinphorin A-chain is only half of cinnamomin A-chain, while their B-chains are the same. Their A-chains are RNA N-glycosidases, and the B-chains are lectins. The intrinsic cytotoxicity of type Ⅱ RIP is greatly dependent on the carbohydrate-binding activity and the specificity of its B-chain. The lectin activity of cinnamomin and cinphorin are investigated and compared with each other. They showed similar hemagglutination activity. Their saccharide binding specificities were studied by hapten inhibition, indicating that they were both galactose-specific. However, N-acetylgalactosamine failed to bind to the two RIPs as ricin/abrin did. The interactions of the two RIPs with specific saccharides were also investigated by fluorescence spectroscopy through which association constants were obtained. Their association constants of galactose or lactose were found to be identical.
出处
《生物化学与生物物理进展》
SCIE
CAS
CSCD
北大核心
2004年第7期650-654,共5页
Progress In Biochemistry and Biophysics
基金
中国科学院基金 (KSCX2 2 0 4)
国家自然科学基金资助项目( 3 9870 186)~~
