Protein incorporation by isolated amphibian oocytes. II. A survey of inhibitors.

Abstract

AbstractA variety of some of the more commonly used metabolic inhibitors and several substances previously found to influence protein incorporation by other types of cells were tested for their effects on protein incorporation by growing oocytes in vitro. With the exception of the uncouplers and the sulfhydryl reagent iodoacetate, the metabolic inhibitors at concentrations of 10 −3 M or less had little influence on sequestering activity. Cycloheximide, at concentrations which essentially abolished all protein synthesis, reduced protein incorporation by only 40–50%. The most pronounced inhibition of protein uptake without apparent cytotoxic side effects was provided by vinblastine and sulfhydryl reagents (especially trivalent arsenicals). The sulfhydryl reagents appeared to exert their effect primarily on the oocyte rather than the proteins of the medium. The results are evaluated both in terms of their relevance to previous studies with other cell systems and their significance towards understanding the mechanisms involved in the incorporation of macromolecules by cells. Finally, a preliminary model of protein incorporation by the oocyte is presented for further testing.