Inhibitory effects of sulfhydryl reagents on acetyl-CoA carboxylase from rat mammary gland
| Autor: | Santosh Gupta, Roland E. Barden, Patricia M. Ahmad, Fazal Ahmad |
|---|---|
| Rok vydání: | 1984 |
| Předmět: |
Coenzyme A
Biophysics Biochemistry Citric Acid Ligases chemistry.chemical_compound Adenosine Triphosphate Mammary Glands Animal Biotin Acetyl Coenzyme A Pregnancy Structural Biology Sulfhydryl reagent Centrifugation Density Gradient Animals Lactation Citrates Molecular Biology Palmitoyl Coenzyme A biology Activator (genetics) Acetyl-CoA carboxylase Molecular biology Rats Pyruvate carboxylase chemistry Enzyme inhibitor biology.protein Hydroxymercuribenzoates Female Adenosine triphosphate Acetyl-CoA Carboxylase |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 789:152-158 |
| ISSN: | 0167-4838 |
| DOI: | 10.1016/0167-4838(84)90199-7 |
| Popis: | Rat mammary gland acetyl-CoA carboxylase (acetyl-CoA:carbon dioxide ligase (ADP forming), EC 6.4.1.2) is rapidly and irreversibly inactivated by micromolar concentrations of S-(4-bromo-2,3-dioxobutyl)-CoA (BDB-CoA) or p-hydroxymercuribenzoate (PHMB). Inhibition of both half reactions (i.e., the biotin carboxylation and the carboxyltransferase) catalyzed by acetyl-CoA carboxylase closely parallels loss in overall activity (malonyl-CoA synthesis). The presence of a substrate or product (acetyl-CoA, ATP, ADP, Pi) or inhibitor (palmitoyl-CoA) does not protect the enzyme from inhibition caused by BDB-CoA or PHMB. On the other hand, citrate, an activator of acetyl-CoA carboxylase, affords substantial protection against inhibition by BDB-CoA and PHMB. Covalent modification by BDB-CoA or PHMB appears to lock acetyl-CoA carboxylase in an inactive conformation (15-30 S) that is unable to undergo citrate-induced self-association into the catalytically competent polymeric form. |
| Databáze: | OpenAIRE |
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