Presence of bound substrate in lactate dehydrogenase from carp liver.
Indian J Biochem Biophys
;
2012 Jun; 49(3): 182-188
Article
Dans Anglais
| IMSEAR
| ID: sea-140234
ABSTRACT
While attempting to purify UDP-galactose 4-epimerase from carp liver extract at pH 8.0, it was observed that the preparation even after dialysis could reduce NAD to NADH, interfering epimerase assay. The NAD reduction activity and the epimerase were co-eluted in a series of chromatographic steps. Mass spectrometric analysis of semi-purified fraction revealed that carp liver lactate dehydrogenase (LDH) contained bound lactate which was converted to pyruvate in the presence of NAD. The enzyme-bound lactate and the association with epimerase stabilized LDH from trypsin digestion and thermal inactivation at 45°C by factors of 2.7 and 4.2 respectively, as compared to substrate-free LDH. LDH and epimerase do not belong to any one pathway, but are the rate-limiting enzymes of two different pathways of carbohydrate metabolism. Typically, strongly associated enzymes work in combination, such as two enzymes of the same metabolic pathway. In that background, co-purification of LDH and epimerase as reloaded in this study was an unusual phenomenon.
Texte intégral:
Disponible
Indice:
IMSEAR (Asie du Sud-Est)
Sujet Principal:
Spectrométrie de masse
/
UDP glucose 4-epimerase
/
Stabilité enzymatique
/
Carpes (poisson)
/
Chromatographie sur gel
/
Acide lactique
/
Acide pyruvique
/
L-Lactate dehydrogenase
/
Foie
/
Animaux
langue:
Anglais
Texte intégral:
Indian J Biochem Biophys
Année:
2012
Type:
Article
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