ISSN:
1432-136X
Keywords:
Phosphofructokinase
;
Protein kinases
;
Glycolyse
;
Gill
;
Crab, Eriocheir sinensis
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Abstract Phosphofructokinase from the posterior gills of the euryhaline crab Eriocheir sinensis acclimated to freshwater is likely regulated in part via phosphorylation induced by endogenous cyclic nucleotide-dependent protein kinases. Phosphofructokinase from gill extracts devoid of low molecular weight compounds by chromatography through a PD10 Sephadex column, incubated in the presence of cAMP or cGMP protein kinases activators (cAMP or cGMP, Mg-ATP and Mg2+), shows an increased catalytic activity. This treatment is accompanied by 32P incorporation into the proteins immunoprecipitated with anti-mammalian phosphofructokinase polyclonal antibodies cross-reacting with the analog crustacean enzyme. Our results indicate that the covalent modification induced by these nucleotide-dependent protein kinases activates the glycolytic enzyme by increasing its affinity for its substrate and, when the activation is specifically due to cAMP-dependent protein kinases, by also reducing the homotropic cooperativity between its multiple substrate binding sites.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00301660
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