Conformational changes induced by the interaction of sodium dodecyl sulfate with bovine plasma albumin

Abstract

The marked effects of neutral and acetate buffer salts on the difference spectra between bovine plasma albumin and the complex with sodium dodecyl sulfate or with sodium dodecanoate are observed. The binding of dodecyl sulfate with high affinity sites in bovine plasma albumin produces a large tyrosyl red shift and a small tryptophyl blue shift in 0.10 M KCl (pH 5.54) and a large tryptophyl blue shift in I = 0.10 sodium acetate buffer (pH 5.623). The 2H 2O perturbation spectra of the complexes with dodecyl sulfate in 0.10 M KCl do not show any changes in masking of tyrosyl and tryptophyl chromophores, up to the molar ratio of added dodecyl sulfate to bovine plasma albumin of 20. The complex of bovine plasma albumin with dodecanoate showes essentially similar results to those with dodecyl sulfate.