Disassembly and reconstitution of yeast 60S ribosomal subunits

Yeast 60S ribosomal subunits have been dissociated by reversible modification with dimethylmaleic anhydride. Treatment with 40 mumol reagent/ml releases 35% of the protein, producing core particles inactive in polyphenylalanine synthesis, which are totally or highly deficient in 17 different proteins. This preparation of residual particles recovers 45% of the original activity upon incubation with the released proteins. The reconstituted particles can be isolated by centrifugation without loss of activity, having the protein composition of the original subunits.