Some Physicochemical Properties of Protein A from <i>Staphylococcus aureus</i>

Abstract

The molecular weight of protein A, isolated from Staphylococcus aureus by lysostaphin digestion, was found to be 42000 by sedimentation equilibrium analyses and by gel chromatography on Sepharose 6B in 6M guanidine hydrochloride. Hydrodynamic studies revealed a frictional ratio of 2.1—2.2 and an intrinsic viscosity of 29 ml/g. Both these parameters suggest that protein A is not a typical globular protein but rather has a markedly extended shape.