Description
Description: This Human Ras-related protein Rap-1b (RAP1B) ELISA Kit employs a two-site sandwich ELISA to quantitate RAP1B in samples. An antibody specific for RAP1B has been pre-coated onto a microplate. Standards and samples are pipetted into the wells and any RAP1B present is bound by the immobilized antibody. After removing any unbound substances, a biotin-conjugated antibody specific for RAP1B 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 RAP1B bound in the initial step. The color development is stopped and the intensity of the color is measured.
Background: The deduced 184-amino acid protein is 95% identical to RAP1A. RAP1B shares several properties with the RAS protein, suggesting that it may bind GTP/GDP and have a membrane location.RAP1B is mainly located at the membrane, but translocates to the cytosol upon activation. In activated platelets, RAP1B interacts with the reorganized actin-based cytoskeleton. RAP1B is activated by phosphorylation, increased intracellular Ca(2+), and by agonist-induced stimulation of Gi, which results in the rapid binding of GTP to RAP1B. RAP1B is posttranslationally modified by the geranylgeranylation of cys181. Further modifications cause proteolytic removal of the last 3 C-terminal amino acids, followed by partial methylation of the remaining terminal cysteinyl carboxyl group