The effects of alcohols on the structure of human glycophorin.
The effects of alcohols on human glycophorin were monitored by circular dichroism, solvent perturbation of absorption spectra, fluorescence of 8-anilino-1-naphthalene sulfonate, and sedimentation equilibrium in the ultracentrifuge. Both ethanol and 2-chloroethanol gradually increase the alpha helix in glycophorin and its sialic acid free counterpart. The same alcohols do not cause a cooperative transition in the structure of the polypeptide chain of glycophorin. Other alcohols also increase the alpha-helix content of glycophorin. Binding of ANS to glycophorin is abolished at relatively low alcohol concentrations. Ethanol at 60% (v/v) reduces the molecular weight ratio of glycophorin and at the same time increases the exposure of tyrosine residues to solvent. These observations indicate a complex mechanism of interaction of weakly protic solvents with this stable membrane protein.
D000438:Alcohols; D000817:Anilino Naphthalenesulfonates; D002942:Circular Dichroism; D006021:Glycophorins; D006801:Humans; D011485:Protein Binding; D011487:Protein Conformation; D011789:Quantum Theory; D012795:Sialoglycoproteins; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
D000438:Alcohols; D000817:Anilino Naphthalenesulfonates; D006021:Glycophorins; D012795:Sialoglycoproteins