title: Phase diagram for acidic conformational states of apomyoglobin.
abstract: The conformation of apomyoglobin under acidic conditions depends on both pH and salt conditions. Using KCl and HCl, a phase diagram for the pH and ionic strength-dependent conformational states was constructed based on the change in the far-ultraviolet circular dichroism. Acid-denatured apomyoglobin consists of two conformational states, the largely unfolded state (UA) and the relatively compact, acidic intermediate state (A). The UA state is stable below pH 3 and at low ionic strength. High ionic strength favors the A state. Because the minimal ionic strength increases significantly with a decrease in pH below 2, the UA state is limited to only a small region between pH 1 and 3.
authors.affiliation: Department of Biology, Faculty of Science, Osaka University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Goto
authors.forename: A L
authors.initials: AL
authors.lastname: Fink
mesh_terms: D000818:Animals; D001059:Apoproteins / Q000378:metabolism*; D006736:Horses; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009211:Myoglobin / Q000378:metabolism*; D009994:Osmolar Concentration; D011487:Protein Conformation
chemical_list: D001059:Apoproteins; D009211:Myoglobin; C010857:apomyoglobin