Interaction of formycin A‐5'‐triphosphate with pyruvate carboxylase

FEBS Letters

Wallace, John C.¹  Coates, John H.²  Attwood, Paul V.¹ 

[1] Department of Biochemistry, University of Adelaide, GPO Box 498, Adelaide, 5001, Australia;Department of Physical and Inorganic Chemistry, University of Adelaide, GPO Box 498, Adelaide, 5001, Australia

关键词: Pyruvate carboxylase;    Formycin triphospate;   

DOI  :  10.1016/0014-5793(84)80566-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Formycin triphosphate (FTP), a fluorescent analogue of ATP, is a competitive inhibitor of chicken liver pyruvate carboxylase with respect to ATP. The chicken liver enzyme is unable to utilise FTP as a substrate at a measureable rate, but FTP is a poor substrate for the sheep liver enzyme. When FTP binds to the enzyme, its fluorescence is enhanced and in this way the formation of enzyme-FTP complexes can be monitored. Using this property of FTP, the effect of Mg²⁺ and acetyl-CoA on the binding of nucleoside triphosphates to the chicken liver enzyme was examined. Mg²⁺ was found to enhance the binding of FTP whilst acetyl-CoA reduced the fluorescence intensity of a mixture of Mg²⁺ enzyme and FTP. Most probably, this was caused by a conformational change in the enzyme which changed the environment of the fluorophore.

【 授权许可】

Unknown