标记肽Dansyl-Gly-Cys-Val-Leu-Ser-OH

描 述：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 (ε₃₄₀ = 4250 M⁻¹cm⁻¹ in 20 mM Tris-HCl, pH 7.5, 10 mM EDTA).

法尼基二磷酸法尼基转移酶(FTase)的荧光底物。该五肽基于H-Ras的c端区域，并在n端连接一个丹酚基团。由于半胱氨酸巯基的法酰化，丹酚基被置于从极性到非极性的分子环境中，这伴随着荧光的增强和丹酚基的较低波长发射最大值的转移。该产物的完全转换导致最大发射波长从565 nm减少到515 nm，同时在505 nm处荧光强度增强13倍。danyl - gcvls可以在505 nm处连续监测法尼酯二磷酸(FPP)存在时的FTase活性，激发波长为340 nm (kcat = 0.5 s⁻¹;Km = 1.4µM)。它是筛选潜在的FTase抑制剂的有用工具。Dns-GCVLS的原液浓度可以通过丹酰部分的消光系数(ε₃₄₀= 4250 M⁻¹cm⁻in 20 mM Tris-HCl, pH 7.5, 10 mM EDTA)计算出来。