Solvent and thermal denaturation of the acidic compact state of apomyoglobin.
The stability of the acidic compact state of apomyoglobin toward the denaturant action of guanidinium hydrochloride and temperature was studied by examining the effects induced on the intrinsic tryptophanyl fluorescence and that of the adduct formed with 1,8-anilinonaphthalenesulfonate (ANS). The results indicated that the disorganization of tryptophanyl environments is caused by a cooperative discrete molecular transition, thus contrasting the assumption that the acidic compact form of apomyoglobin might be a molten globule state. The unfolding of the ANS binding regions was found to involve, at least, two stages over a wide range of denaturant concentrations.
Sirangelo
I
I
Dipartimento di Biochimica e Biofisica, Seconda Università di Napoli, Italy.
Bismuto
E
E
Irace
G
G
D000817:Anilino Naphthalenesulfonates; D000818:Animals; D001059:Apoproteins / Q000737:chemistry*; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes; D006736:Horses; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009211:Myoglobin / Q000737:chemistry*; D011489:Protein Denaturation; D017510:Protein Folding; D012997:Solvents
D000817:Anilino Naphthalenesulfonates; D001059:Apoproteins; D005456:Fluorescent Dyes; D009211:Myoglobin; D012997:Solvents; C010857:apomyoglobin; C027132:1-anilino-8-naphthalenesulfonate