Comparison of nitrophenylethyl and hydroxyphenacyl caging groups
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Updated: Oct 7, 2026

Design, Synthesis, and Photochemical Properties of Clickable Caged Compounds
Published on: October 15, 2019
1Department of Chemistry, Room 220, Melvin Calvin Laboratory, University of California, Berkeley, CA 94720, USA.
Abstract:
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.
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