Sleep, neuropeptides and proteases

Neuropeptides have a fundamental role on sleep-wake cycle control and their proteolytic processing regulates their actions. Proteases are essential for the metabolism of neuropeptides, by release either from active or inactive precursors or by the inactivation of active neuropeptides. Using the Merops, a peptidase database, the Brenda Enzyme Database, the Expasy Bioinformatics Resource Portal and the published literature on normal sleep physiological regulation, we performed a review aimed to identify the proteases that can metabolize neuropeptides involved in regulating the sleep-wake cycle and could be altered during and after sleep deprivation.