Tuesday, 4 January 2011

First FRET-based Elastase activity assay kit

AnaSpec has introduced the SensoLyte Green Elastase Assay Kit - the first FRET-based Elastase activity assay kit in the industry. This kit employs a natural substrate, elastin that is labelled with the 5-FAM fluorophore and the QXL 520 quencher.

Proteolytic cleavage of labelled elastin separates the donor from the quencher and yields brightly green fluorescence, which can be continuously monitored at excitation/emission (Ex/Em) = 488 nm/520 nm. Increase in fluorescence intensity is directly proportional to elastase activity. The kit can be used to continuously measure the kinetics of elastase activity. As well, this highly sensitive kit is homogeneous – it does not require any separation steps.

Elastases catalyze the hydrolysis of elastin, the chief constituent of elastic fibers that together with collagen determines the mechanical properties of connective tissue. Elastases have many other natural substrates these include proteoglycans, collagens and fibronectin.1-4 Implicated in many diseases such as pulmonary emphysema, cystic fibrosis, infections, inflammation and atherosclerosis, elastases are considered important drug targets.5

AnaSpec, Eurogentec Group also provides another green emitting elastase assay, the SensoLyte Rh110 Elastase Assay Kit. This assay uses a substrate that is labeled with a fluorogenic dye called Rh110 (rhodamine 110). Upon cleavage by elastase, the substrate generates free Rh110 fluorophore, which has a bright green fluorescence. Signal can be detected at Ex/Em =490/520 nm. The longer wavelength spectra and higher extinction coefficient of this kit and the SensoLyte Green Elastase kits provide greater sensitivity and less interference from other reaction components.

1.Kafienah, W. et al. Biochem J. 330, 897 (1998).
2.Carlo, L. et al. J. Biol. Chem. 255, 12006 (1980).
3.Mainardi, CL. et al. J. Biol. Chem. 255, 5435 (1980).
4.McDonald, JA. et al. J. Biol. Chem. 255, 8848 (1980).
5. Bieth, JG. J. Soc. Biol. 195, 173 (2001).