Complex proteomes enzyme activities

Activity-based protein profiling (ABPP) is a chemical proteomic strategy in which active-site-directed covalent probes are used to profile the functional states of enzymes in complex proteomes. Activity-based probes (ABPs) can distinguish active enzymes from their inactive zymogens or inhibitor-bound forms. They contain a reactive group intended to modify enzyme active sites covalently and a reporter group (typically rhodamine or biotin) that assists in detection and identification of protein targets. 

Adam GC, Burbaum J, Kozarich JW et al (2004) Mapping enzyme active sites in complex proteomes. J Am Chem Soc 126 1363-1368... 

In the recent literature, many examples of A/BPs containing benzophenones can be found. A first example concerns the study of HDACs. These enzymes catalyze the hydrolysis of acetylated lysine amine side chains in histones and are thus involved in the regulation of gene expression. There are approximately 20 human HDACs, which are divided into three classes (I, II, and III). Class I and II HDACs are zinc-dependent metallohydrolases that do not form a covalent bond with their substrates during their catalytic process, which is similar to MMPs. It has been found that hydroxamate 65 (SAHA, see Fig. 5) is a potent reversible inhibitor of class I and II HDACs. In 2007, Cravatt and coworkers reported the transformation of SAHA into an A/BP by installment of a benzophenone and an alkyne moiety, which resulted in SAHA-BPyne (66) [73]. They showed that the probe can be used for the covalent modification and enrichment of several class I and class II HDACs from complex proteomes in an activity-dependent manner. In addition, they identified several HDAC-associated proteins, possibly arising from the tight interaction with HDACs. Also, the probe was used to measure differences in HDAC content in human disease models. Later they reported the construction of a library of related probes and studied the differences in HDAC labeling [74], Their most... 

Sieber SA, Mondala TS, Head SR, Cravatt BF. Microarray platform for proliUng enzyme activities in complex proteomes. J. Am. Chem. Soc. 2004 126 15640-15641. 

Adam, G. C., Sorensen, E. J., Cravatt, B. F. (2002b). Trifunctional chemical probes for the consolidated detection and identification of enzyme activities from complex proteomes. Molecular Cellular Proteomics MCP, 1, 828—835. 

Activity-based Protein Profiling (ABPP) - A Chemical Strategy for the Global Profiling of Enzyme Activities in Complex Proteomes... 

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