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Solvent and thermal denaturation of the acidic compact state of apomyoglobin
Author(s) -
Sirangelo Ivana,
Bismuto Ettore,
Irace Gaetano
Publication year - 1994
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(94)80107-x
Subject(s) - chemistry , molten globule , denaturation (fissile materials) , adduct , solvent , guanidine , fluorescence , crystallography , circular dichroism , organic chemistry , nuclear chemistry , physics , quantum mechanics
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.