The molecular action of ricin A chain involves cleavage of the N-glycosidic bond between ribose and the adenine 4324 nucleotides from the 5' end of mammalian 28 S rRNA (Endo, Y., and Tsurugi, K. (1987) J. Biol. Chem. 262, 8128-8130). In this paper, four ricin- and abrin-resistant Chinese hamster ovary cell mutants that possess ribosomes resistant to this N-glycosidase action are described. Thre...

A new crystalline form of abrin has been obtained from the most toxic constituent of the seed extract of Abrus precatorius. An x-ray diffraction study shows that the toxin crystallizes in a monoclinic unit cell of probable symmetry P21 and parameters (I = 113 A, b = 72 A, c = 71 A, and /3 = 103”. The asymmetric unit contains 2 protein molecules of molecular weight 63,800 and has a solvent conte...

The illicit usage of toxic substances is increasing rapidly around the world, creating a need for comprehensive chemical methods for detecting and quantitating toxic agents that might be used in criminal activities or terror attacks. There are several toxic proteins that could potentially be used in bioterrorism or biocrime. For example, the plant toxins ricin and abrin are readily available, v...

Although muscle cell fusion was shown to be an energy-requiring process, release of myoblasts from an EGTA fusion block could be accomplished with Earle's balanced salt solution (containing 1.8 mM Ca++) free of glucose or any other energy-produced metabolite. The effect of concanavalin A, abrin, and the lectins from wheat germ, soybean, and Lens culinaris on myoblast fusion was examined with sy...