GA21366

Dansyl-Gly-Cys-Val-Leu-Ser-OH

Also known as (2S)-2-[[(2S)-2-[[(2S)-2-[[(2R)-2-[[2-[[5-(dimethylamino)naphthalen-1-yl]sulfonylamino]acetyl]amino]-3-sulfanylpropanoyl]amino]-3-methylbutanoyl]amino]-4-methylpentanoyl]amino]-3-hydroxypropanoic acid

Fluorogenic substrate for farnesyl diphosphate farnesyltransferase (FTase)· The pentapeptide is based on the C-terminal region of H-Ras with a dansyl group attached to the N-terminus· Due to farnesylation of the cysteine thiol group the dansyl group is placed from a polar to a non-polar molecular environment which is accompanied by an enhancement of fluorescence and a shift to a lower wavelength emission maximum of the dansyl group· Complete conversion of the product results in a decrease of the emission maximum wavelength from 565 nm to 515 nm together with a 13-fold enhancement in fluorescence intensity at 505 nm· Dansyl-GCVLS can be used for continuously monitoring FTase activity in the presence of farnesyl diphosphate (FPP) at 505 nm using an excitation wavelength of 340 nm (kcat = 0·5 s?¹; Km = 1·4 µM)· It represents a useful tool for screening potential FTase inhibitors· The substrate is highly specific to FTase and is not recognized by geranylgeranyl transferse type I (GGTase I)·Concentrations of stock solutions of Dns-GCVLS can be calculated from the extinction coefficient of the dansyl moiety (ε??? = 4250 M?¹cm?¹ in 20 mM Tris-HCl, pH 7·5, 10 mM EDTA)