Lower activation energy for sliding of F-actin on a less thermostable isoform of carp myosin.
J Biochem
; 120(4): 788-91, 1996 Oct.
Article
em En
| MEDLINE
| ID: mdl-8947842
ABSTRACT
We have examined the temperature-dependence of sliding velocity of fluorescent F-actin on myosins isolated from 10 degrees C- and 30 degrees C-acclimated carp. Activation energies for the sliding of F-actin were 63 and 111 kJ/mol for the 10 degrees C- and 30 degrees C-acclimated carp myosins, respectively. Arrhenius plots of the sliding velocity from 10 degrees C- and 30 degrees C-acclimated carp myosin were shown to intersect at high temperature (about 30 degrees C). The thermostability estimated by measuring the Ca(2-)-ATPase activity was less for myosin from 10 degrees C- than 30 degrees C-acclimated carp. We suggest that a less thermostable structure in cold-acclimated carp myosin results in a reduced activation energy for the contractile process, which allows the F-actin to slide fast even at low temperatures.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Carpas
/
Aclimatação
/
Proteínas Musculares
Limite:
Animals
Idioma:
En
Revista:
J Biochem
Ano de publicação:
1996
Tipo de documento:
Article