In this protease substrate, collagen is heavily labeled with a fluorescein derivative, resulting in almost total quenching of the conjugate's fluorescence. Protease-catalyzed hydrolysis relieves this quenching conjugate, yielding brightly green fluorescent dye-labeled peptides. The increase in fluorescence intensity is directly proportional to protease activity. Collagen, Type IV should be particularly useful in the development of HTS assays for screening Gelatinase A (MMP-2) and Gelatinase A inhibitors, as well as for other gelatinases and collagenases that specifically degrade (Type IV) Collagen. Additionally, lightly fluorescein-labeled collagen may be useful for continuous assays monitored by fluorescence polarization.
Ref: Sela MN, et al. (2003). Enzymatic degradation of collagen-guided tissue regeneration membranes by periodontal bacteria. Clin Oral Implants Res 14, 263-8.; Kraft PJ, et al. (2001). Fluorescence polarization assay and SDS-PAGE confirms matrilysin degrades fibronectin and collagen IV whereas gelatinase A degrades collagen IV but not fibronectin. Connect Tissue Res 42, 149-63; Otsuka K, et al. (1997). An improved assay method for fibroblast gelatinolytic enzyme. J Nihon Univ Sch Dent 39, 182-90.