Du X, Frei H, Kim S H
Department of Chemistry, Room 220, Melvin Calvin Laboratory, University of California, Berkeley, CA 94720, USA.
Biopolymers. 2001;62(3):147-9. doi: 10.1002/bip.1007.
Nitrophenylethyl (NPE)- and hydroxyphenacyl (HPA)-caged nucleotides were employed in a time-resolved Fourier transform IR spectroscopy study on Ras-catalyzed guanosine triphosphate (GTP) hydrolysis. A fast kinetic component was observed following the photolysis of NPE-caged nucleotides in the NPE-GTP-Ras complex. However, this kinetic component was not observed in the HPA-GTP-Ras experiment. This fast kinetic component was likely due to a chemical reaction between Ras and the detached caging group, nitrosoacetophenone. This communication serves as a note of caution in interpreting spectral changes and kinetic behavior of the enzymatic systems employing NPE-caged compounds.
硝基苯乙基（NPE）和羟基苯甲酰（HPA）笼蔽核苷酸被用于一项关于Ras催化的三磷酸鸟苷（GTP）水解的时间分辨傅里叶变换红外光谱研究。在NPE-GTP-Ras复合物中NPE笼蔽核苷酸光解后观察到一个快速动力学成分。然而，在HPA-GTP-Ras实验中未观察到该动力学成分。这个快速动力学成分可能是由于Ras与脱离的笼蔽基团亚硝基苯乙酮之间的化学反应。本通讯旨在提醒在解释使用NPE笼蔽化合物的酶系统的光谱变化和动力学行为时需谨慎。
