期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1978
卷号：75
期号：3
页码：1096-1100
DOI：10.1073/pnas.75.3.1096
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Studies on the disulfide bond connecting the two polypeptide chains of ricin are reported. Reduction of this bond in the native protein requires approximately 50-fold more mercaptoethanol than the reduction of the bond in the protein denatured by sodium dodecyl sulfate. An improved procedure for the formation of this disulfide bond from recombined chains is reported. A and B chains spontaneously and rapidly reassociate into a stable complex with a sedimentation velocity similar to that of native oxidized ricin before the disulfide bond reforms. The mixture of both chains also behaves on Bio-Gel P-100 like native oxidized ricin. However, the complex formed by the two chains, assayed before the disulfide bond can reform, and reduced ricin, carboxymethylated to prevent reoxidation, shows a significant decrease in toxicity to mice and a decrease in ability to inhibit protein synthesis in HeLa cells in culture.
