title: Structural stability of glycophorin. Effects of heat and guanidine . HCl.
abstract: The effects of guanidine hydrochloride and high temperature on human glycophorin and sialic acid-free glycophorin were monitored by circular dichroism, viscosity, and fluorescence of 1-anilino-8-naphthalane sulfonate (ANS). The following observations were made: 1. Glycophorin and its sialic acid-free counterpart are unusually stable to both guanidine . HCl and heat. 2. CD and viscosity measurements indicate that guanidine . HCl neither causes a cooperative unfolding nor generates a random coil. 3. The ANS binding site is much more sensitive to guanidine . HCl than the ellipticity at 220 nm (theta 220). 4. The effect of temperature on CD is reversible whereas the effect of guanidine . HCl is not. 5. The carbohydrate moiety influences the viscosity, and also contributes to the changes in theta 220 when solutions of glycophorin are heated. These unusual properties indicate a complex mechanism of unfolding for this structurally stable macromolecule.
mesh_terms: D004355:Drug Stability; D006021:Glycophorins; D006146:Guanidines; D006358:Hot Temperature; D006801:Humans; D012794:Sialic Acids; D012795:Sialoglycoproteins; D014508:Urea
chemical_list: D006021:Glycophorins; D006146:Guanidines; D012794:Sialic Acids; D012795:Sialoglycoproteins; D014508:Urea