| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a new ribosome-inactivating protein (RIP) with two chains, production methods and preparations thereof. <P>SOLUTION: Disclosed is a novel non-toxic ribosome-inactivating protein (RIP) of plant origin being basic Nigrin 1, Ebulin 1 and Racemosin b, which has two chains in the extra-cellular region and is capable of interacting with a ribonucleic acid in a cell-free system and causing the inhibition of the biosynthesis of proteins, wherein the protein comprises two chains A and B, chain A having an N-glucosidase activity of the ribosomal ribonucleic acid, and chain B having a lectin activity, both chains being joined by disulfide bridges. A non-toxic protein featured by binding to carrier molecules (antibodies, hormones or other proteins) recognizable through a membrane receptor existing in target cells, allowing a specific and selective action of the chain A to the target cells by inactivation of ribonucleic acids of some their ribosomes, on the other hand, substantially avoiding the indiscriminating attack of the RIP to cells which is not selected by the carrier molecule and toxicity is lacked in the extra-cellular region, production methods and preparations thereof are disclosed. <P>COPYRIGHT: (C)2004,JPO |
