GTP Probes

GTPases comprise a diverse family of enzymes that participate in a variety of cellular processes including signal transduction, protein synthesis, and intracellular transport. GTPases typically participate in these processes as binary switches; activating a process in the GTP-bound state and inactivating a process in the GDP bound state. Importantly, the deregulation of the GTP/GDP cycle for a number of GTPases are known to be associated with cancers.

ActivX has developed a desthiobiotin acyl phosphate GTP probe that covalently modifies GTPases in the active site. Profiling numerous proteomes has lead to identification of members from most sub-families of GTPases, suggesting that the probe could be a useful tool for profiling the distribution of GTPases.

GTP probe coverage

The primary labeling site of the GTP probe is in the phosphate binding region of GTPases. For some GTPases, probe-labeling at this site is sensitive to EDTA-dependent nucleotide exchange, raising the possibility that the GTP probe could be used to monitor the activity of GTPases in proteomes.