Attwood P V, Coates J H, Wallace J C
FEBS Lett. 1984 Sep 17;175(1):45-50. doi: 10.1016/0014-5793(84)80566-9.
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.
三磷酸间型霉素（FTP）是ATP的一种荧光类似物，相对于ATP而言，它是鸡肝丙酮酸羧化酶的竞争性抑制剂。鸡肝酶无法以可测量的速率将FTP用作底物，但FTP是绵羊肝酶的不良底物。当FTP与该酶结合时，其荧光会增强，通过这种方式可以监测酶 - FTP复合物的形成。利用FTP的这一特性，研究了Mg2+和乙酰辅酶A对核苷三磷酸与鸡肝酶结合的影响。发现Mg2+增强了FTP的结合，而乙酰辅酶A降低了Mg2+、酶和FTP混合物的荧光强度。最有可能的是，这是由酶的构象变化引起的，该变化改变了荧光团的环境。
