Amplite(TM) Fluorimetric Renin Assay Kit *Red Fluorescence*

Renin is an enzyme that participates in the body's renin-angiotensin system (RAS) that mediates extracellular volume and arterial vasoconstriction. It regulates blood pressure and electrolyte homoeostasis. Angiotensin II constricts blood vessels leading to increased blood pressure. It also increases the secretion of ADH and aldosterone, and stimulates the hypothalamus to activate the thirst reflex. An over-active renin-angiotension system leads to vasoconstriction and retention of sodium and water. Renin has been identified to be an attractive target for the treatment of hypertension. The Amplite(TM) Renin Assay Kit provides a convenient assay for high throughput screening of renin inhibitors and renin activity using our proprietary Tide Fluor(TM) 3 (TF3)/Tide Quencher(TM) 3 (TQ3) fluorescence resonance energy transfer (FRET) peptide. In the FRET peptide, the fluorescence of TF3 is quenched by TQ3. Upon cleavage into two separate fragments by renin, the fluorescence of TF3 is recovered, and the fluorescent signal can be easily monitored by a fluorescence microplate reader. This assay is about fifty fold more sensitive than an EDANS/DABCYL-based assay. With the Amplite(TM) Renin Assay Kit, we have detected as little as 1ng renin in a 100 µL reaction volume. However, the selectivity of the rennin substrate used in the kit has not been thoroughly tested. It may also response to other proteases since peptide-based protease substrates generally have low selectivity.