Role of Ser530, Arg292, and His662 in the allosteric behavior of rabbit muscle phosphofructokinase
| Autor: | Simon H. Chang, Robert G. Kemp |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Allosteric regulation
Molecular Sequence Data Biophysics Biology Biochemistry Enzyme activator Structure-Activity Relationship Adenosine Triphosphate Allosteric Regulation Phosphofructokinase-1 Muscle Type Fructosediphosphates Animals Phosphofructokinase 1 Binding site Molecular Biology chemistry.chemical_classification Binding Sites Sequence Homology Amino Acid Activator (genetics) Fructosephosphates Cell Biology Enzyme Activation Enzyme Allosteric enzyme chemistry Amino Acid Substitution biology.protein Mutagenesis Site-Directed Rabbits Phosphofructokinase |
| Zdroj: | Biochemical and biophysical research communications. 290(2) |
| ISSN: | 0006-291X |
| Popis: | Fructose-2,6-bisphosphate (Fru-2,6-P(2)) is a potent allosteric activator of the ATP-dependent phosphofructokinase (PFK) in eukaryotes. Based on the sequence homology between rabbit muscle PFK and two bacterial PFKs and the crystal structures of the latter, Ser(530), Arg(292) and His(662) of the rabbit enzyme are implicated as binding sites for Fru-2,6-P(2). We report here the effects of three mutations, S530D, R292A, and H662A on the activation of rabbit muscle PFK by Fru-2,6-P(2). At pH 7.0 and the inhibitory concentrations of ATP, the native enzyme gives a classic sigmoidal response to changes in Fru-6-P concentration in the absence of Fru-2,6-P(2) and a nearly hyperbolic response in the presence of the activator. Under the same conditions, no activation was seen for S530D. On the other hand, H662A can be activated but requires a 10-fold or higher concentration of Fru-2,6-P(2). Limited activation was observed for mutant R292A. A model illustrating the sites for recognition of Fru-2,6-P(2) in rabbit muscle PFK as well as the mechanism of allosteric activation is proposed. |
| Databáze: | OpenAIRE |
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