Publicação: REEVALUATION OF CHLORIDES REGULATION OF HEMOGLOBIN OXYGEN-UPTAKE - THE NEGLECTED CONTRIBUTION OF PROTEIN HYDRATION IN ALLOSTERISM
Carregando...
Data
Autores
Orientador
Coorientador
Pós-graduação
Curso de graduação
Título da Revista
ISSN da Revista
Título de Volume
Editor
Natl Acad Sciences
Tipo
Artigo
Direito de acesso
Acesso restrito
Resumo
We have measured hemoglobin oxygen uptake vs. The partial pressure of oxygen, with independently controlled activities of chloride and water. This control is effected by combining different concentrations of NaCl and sucrose in the bathing solution to achieve: (i) water activities were varied and CI- activity was fixed, (ii) both water and CI- activities were varied with a traditional NaCI titration, or (iii) CI- activities were varied and water activity was fixed by adding compensating sucrose. Within this analysis, the CI--regulated loading of four oxygens can be described by the reaction Hb.CI- + 4 O-2 + 65 H2O reversible arrow Hb.4O(2).65H(2)O + CI-. The dissociation of a neatly integral chloride, rather than the nonintegral 1.6 chlorides inferred earlier from simple salt titration, demonstrates the need to recognize the potentially large contribution from changes in water activity when titrating weakly binding solutes. The single-chloride result might simplify structural considerations of the action of CI- in hemoglobin regulation.
Descrição
Palavras-chave
Idioma
Inglês
Como citar
Proceedings of the National Academy of Sciences of the United States of America. Washington: Natl Acad Sciences, v. 91, n. 22, p. 10517-10520, 1994.
