Salt-induced refolding of myoglobin at acidic pH: molecular properties of a partly folded intermediate.
The molecular properties of the salt-induced partly folded acidic state of apomyoglobin as well as myoglobin were investigated by fluorescence and circular dichroism of the extrinsic fluorophore 1,8-anilinonaphthalenesulfonate. The occurrence of a fluctuating tertiary structure ("molten globule") at acidic pH in the presence of salt was suggested by the disappearance of the dichroic activity of the fluorophore bound to the partly folded protein. Moreover, the structure of the intermediate is not influenced by the presence of heme, thus suggesting that heme is not crucial in the early stage of myoglobin folding.
Bismuto
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Dipartimento di Biochimica e Biofisica, Università di Napoli, Italy.
Sirangelo
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I
Irace
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G
D000817:Anilino Naphthalenesulfonates; D000818:Animals; D002942:Circular Dichroism; D005456:Fluorescent Dyes; D006736:Horses; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009211:Myoglobin / Q000737:chemistry*; D009994:Osmolar Concentration; D011487:Protein Conformation; D011489:Protein Denaturation; D012965:Sodium Chloride / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013816:Thermodynamics
D000817:Anilino Naphthalenesulfonates; D005456:Fluorescent Dyes; D009211:Myoglobin; D012965:Sodium Chloride; C027132:1-anilino-8-naphthalenesulfonate