Location of the sulfhydryl groups involved in disulfide interaction between the neighboring proteins L6 and L29 in mammalian ribosomes. S-cleavage of the cyanylated proteins in polyacrylamide gels after separation by dodecylsulfate gel electrophoresis.

摘要: Proteins L6 and L29 occupy closely adjacent sites in mammalian 60-S ribosomal subparticles are easily cross-linked by intermolecular disulfide bond formation. For locating the interacting thiols within polypeptide chains dissociated proteins obtained from isolated complex were subjected to S-cleavage following [14C]cyanylation of two cysteine residues. Four split products [14C]cyanylated dodecylsulfate gel electrophoresis. Two these could be identified autoradiography as selectively labeled C-terminal fragments. unequivocal assignment fragments parent proteins, a simple generally applicable method cleaving cyanylated polyacrylamide for subsequent diagonal analysis was developed. The experiments indicated that sulfhydryl group with is located at distance approximately 80 amino acid residues N-terminus. In intact ribosome this sequence contains clostripain-sensitive trypsin-sensitive portion protein more or less exposed surface. case L29, 40 C-terminal.