41] Chemiluminescent probes for singlet oxygen in biological reactions

Abstract

Publisher Summary This chapter discusses the chemiluminescent (CL) probes for singlet oxygen in biological reactions. The CL probe t -MVP is specifically designed as an analog for the singlet oxygen-initiated CL of 7, 8-diol. Because of the t -MVP's structural similarity with 7, 8-diol and the broad structural specificities of cytochrome P - 450s, t -MVP is capable of being metabolized by the same enzymes, which catalyzed the production of a chemiluminescent intermediate from 7, 8-diol. This may not be the case in all biological reactions. One of the primary characteristics of enzymatic reactions is substrate specificity, and therefore, it may be necessary to tailor a CL probe specifically for application with a particular enzyme. There are two general scenarios for the production of free singlet oxygen in biological reactions. The first is where O 2 is produced through either photosensitization or enzymatic reactions and released free into solution to react randomly with cellular constituents. As there is no substrate specificity, general CL probes should be sufficient to distinguish this case. The second is where O 2 or singlet oxygen equivalents are produced and reacted with a bound substrate within the active site of the enzyme, necessitating the use of a CL probe with molecular structure that can be recognized and bound by the enzyme prior to reaction.