Effect of single amino acid substitutions on the thermal unfolding of P22 tailspike protein

Abstract

We examined the thermal unfolding of four different mutant tailspike proteins of phage P22, which fold and mature more efficiently than the wild type. The mutations did not affect the unfolding of native protein to the intermediate conformation, but did affect the unfolding of intermediate to fully denatured monomer. For three mutations this process was more rapid than that for the wild type. The results suggest that the mutations which increa狀 the efficiency of folding and maturation of the tailspike in vivo do not necessarily decrease the thermal unfolding process of the native proteins in vitro.