[Effect of polyene antibiotics on protein synthesis by free and membrane-bound ribosomes of Candida albicans]

Abstract

Polyene antibiotics (levorin, nistatin, amphotericin B) inhibit protein synthesis at concentrations decreasing 14C-amino acid incorporation into Candida albicans protoplasts by 30--60%, the depression of membrane permeability beginning earlier than protein synthesis inhibition. Fractionation of protoplast lysates revealed that protein synthesis by free ribosomes was inhibited by antibiotics stronger than in case of membrane-bound ribosomes. It is supposed that different response of two ribosome classes for polyenes-induced damages is due to different sensitivity of free and membrane-bound ribosomes to the decrease of intracellular K+ concentration.