Description
Introduction: Kallikreins (KLKs) are a subgroup of trypsin-like serine proteases and are implicated in carcinogenesis. Originally described from human urine as a hypotensive agent and later from the pancreas, kallkreins were given the Greek name for pancreas, kallikreas. Kallikrein 6, also known as Zyme, Neurosin, PRSS9, myelencephalon-specific protease (MSP) and protease M, is a trypsin-like serine proteinase. Kallikrein 6 was originally described from the brain as an enzyme involved in degradation of amyloid plaque protein (APP) and hK6 was thought to be a beta secretase. Kallikrein 6 was shown to be elevated in the sera patients with Alzheimer's disease and Parkinson's disease and in animal models of multiple sclerosis. The neuronal protein alpha-synuclein was shown to be cleaved by hK6, as has APP and hK6 has been implicated in vascular morphogenesis and angiogenesis. MSP has also been shown to rapidly degrade myelin-specific protein, laminin and fibronectin. Kallikrein 6 is 3 found in greatest abundance in the brain and neuronal tissues, with lesser levels in the kidney, thymus, spleen and lymph nodes. Human breast milk is reported to contain high levels of Kallikrein 6 and hK6 has been purified from cerebral spinal fluid (CSF). Less stringent PCR detects hK6 in many tissues and analysis of cell lines by Western blot shows that many cell lines make hK6. Endogenous inhibitors include kallistatin, protein-C inhibitor and 1-proteinase inhibitor, although Kallikrein 6 can be found complexed to a number of different proteinase inhibitors.
Principle of the Assay: The microtiter plate provided in this kit has been pre-coated with an antibody specific to KLK 6. Standards or samples are then added to the appropriate microtiter plate wells with a biotin-conjugated antibody preparation specific for KLK 6 and Avidin conjugated to Horseradish Peroxidase (HRP) is added to each microplate well and incubated. Then a TMB (3,3',5,5' tetramethyl-benzidine) substrate solution is added to each well. Only those wells that contain KLK 6, biotin-conjugated antibody and enzyme-conjugated Avidin will exhibit a change in color. The enzyme-substrate reaction is terminated by the addition of a sulphuric acid solution and the color change is measured spectrophotometrically at a wavelength of 450 nm +/- 2 nm. The concentration of KLK 6 in the samples is then determined by comparing the O.D. of the samples to the standard curve