Transition state of an unfolding step in human cyanomet myoglobin.
Biochim Biophys Acta
; 1162(1-2): 93-8, 1993 Mar 05.
Article
em En
| MEDLINE
| ID: mdl-8448200
ABSTRACT
We studied an unfolding step of cyanomet myoglobin (Mb) unfolding, for demonstrating dynamical structural changes in the transition state of the process. Three leucine-->alanine mutant Mbs (L29A, L72A and L104A) were prepared for this study. The urea-induced largely monophasic process was monitored by absorption spectroscopy. Linear relations between [urea] and the activation energy (delta G not equal to) of the relaxation for all the Mbs showed that the slope m not equal to urea (= delta(delta G not equal to)/delta[urea])) was altered by either reduction of pH or the L-->A mutations. Thermodynamic interpretations of the changes in m not equal to urea led to a conclusion that the exposed surface area of Mb in the transition state was determined by both protein-core stability and pH conditions. We also performed urea- and acid-denaturation experiments, and gave some inspections on differences between mutational effects on the structure of the transition state and the denatured state.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Metamioglobina
Limite:
Humans
Idioma:
En
Revista:
Biochim Biophys Acta
Ano de publicação:
1993
Tipo de documento:
Article
País de afiliação:
Japão