Influence of Ca2+ on kinetics and thermodynamics of the NADPH-dependent microsomal lipid peroxidation.
Indian J Biochem Biophys
;
1996 Oct; 33(5): 377-83
Article
in English
| IMSEAR
| ID: sea-28351
ABSTRACT
The effect of Ca2+ on kinetics and thermodynamics of lipid peroxidation in microsomes prepared from liver of male Swiss albino mice (7-8 weeks old) was studied. Ca2+ was found to increase the Vmax in temperature dependent manner. Michaelis-Menten constant (Km) also increased with temperature. However, the linearity and extent of change in Km remained unaffected in presence of Ca2+, and was suggestive of non-competitive and mixed type of activation. The activation constant (Ka) obtained by the replotting of slopes of the Lineweaver-Burk plots against the reciprocal of Ca2+ concentration showed linear variation with temperature. The linear pattern of Arrhenius plots indicated non-involvement of parallel reactions of other intermediate species in the lipid peroxidation. Thermodynamic parameters delta H degree, delta S degree and delta G degree, associated with lipid peroxidation process were studied. The positive value of delta H degree is suggestive of the endothermic nature of the process. It appears that the NADPH induced lipid peroxidation is an entropy driven process.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Thermodynamics
/
Male
/
Microsomes, Liver
/
Kinetics
/
Lipid Peroxidation
/
Calcium
/
NADPH-Ferrihemoprotein Reductase
/
Animals
/
Mice
/
NADP
Language:
English
Journal:
Indian J Biochem Biophys
Year:
1996
Type:
Article
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