Description
Description: This assay employs a two-site sandwich ELISA to quantitate FPGS in samples. An antibody specific for FPGS has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any FPGS present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for FPGS is added to the wells. After washing, Streptavidin conjugated Horseradish Peroxidase (HRP) is added to the wells. Following a wash to remove any unbound avidin-enzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of FPGS bound in the initial step. The color development is stopped and the intensity of the color is measured.
Overview: Folylpolyglutamate synthase, also known as FPGS encodes the folylpolyglutamate synthetase enzyme. This enzyme has a central role in establishing and maintaining both cytosolic and mitochondrial folylpolyglutamate concentrations and, therefore, is essential for folate homeostasis and the survival of proliferating cells. The enzyme folylpoly-gamma-glutamase synthethase (FPGS) plays an important role in the intracellular polyglutamation of the disease-modifying antirheumatic drug methotrexate (MTX) and the length of the polyglutamated MTX product correlates with the time that MTX resides in the cell. The glutamates are released from MTX by activity of the enzyme gamma-glutamyl-hydrolase (GGH), thereby allowing the efflux of MTX