||Factor XIII is purified from fresh frozen human plasma by a modification of the procedures described by Folke and Lorand involving barium citrate, ammonium sulfate and glycine precipitations, ion exchange chromatography and gel filtration.
||Factor XIII is the zymogenic form of the glutaminyl-peptide g-glutamyl transferase?factor XIIIa?(fibrinoligase, plasma transglutaminase, fibrin stabilizing factor, E.C. 18.104.22.168). Factor XIII is unique among transamidases in that it is a zymogen in vivo. Factor XIII is found both extracellularly in plasma and intracellularly in platelets, megakaryocytes, monocytes, placenta, uterus, liver and prostrate tissues. Plasma factor XIII is synthesized in the liver and circulates as a tetramer (Mr=320,000), composed of 2 pairs of nonidentical subunits (A2B2). The intra-cellular forms are synthesized in the tissues where they reside as dimers (Mr=146,000) of 2 identical A chains (A2). The A subunits of plasma and intracellular forms of factor XIII are functionally identical. The A subunit contains 6 free sulfhydryl groups one of which is the active site.?
||50% (vol/vol) glycerol/500uM EDTA
||Factor XIII is homogeneous as judged by SDS PAGE, with a specific activity of ~50 units/mg.
||>95% by SDS-PAGENOT tissue/cell culture grade. Not tested for endotoxin.
||Factor XIII is supplied in 50% glycerol containing 0.5 mM EDTA, for storage at -20°C .