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Kallikrein B, plasma
Plasma kallikrein, Fletcher factor
Plasma prekallikrein is a glycoprotein that participates in the surface-dependent activation of blood coagulation, fibrinolysis, kinin generation and inflammation. It is synthesized in the liver and secreted into the blood as a single polypeptide chain. Plasma prekallikrein is converted to plasma kallikrein by factor XIIa by the cleavage of an internal Arg-Ile bond. Plasma kallikrein therefore is composed of a heavy chain and a light chain held together by a disulphide bond. The heavy chain originates from the amino-terminal end of the zymogen and contains 4 tandem repeats of 90 or 91 amino acids. Each repeat harbors a novel structure called the apple domain. The heavy chain is required for the surface-dependent pro-coagulant activity of plasma kallikrein. The light chain contains the active site or catalytic domain of the enzyme and is homologous to the trypsin family of serine proteases. Plasma prekallikrein deficiency causes a prolonged activated partial thromboplastin time in patients. [provided by RefSeq, Jul 2008] (from
Feener et al., Fukuoka, Japan. In Diabetes, Oct 2015
Plasma prekallikrein (PPK) and plasma kallikrein (PKal) were increased twofold and 11.0-fold (both P < 0.0001), respectively, in vitreous from subjects with DME compared with those with a macular hole (MH).
Interestingly, it was unexpectedly found that Fletcher factor is plasma prekallikrein and Fitzgerald factor is high-molecular-weight kininogen; components of the kinin-generating system, thus disclosing intimate relationships among clotting, fibrinolysis and kinin generation which may be viewed as body's defense reactions against injury.
extensive cytoplasmic expression of tissue prokallikrein and plasma prekallikrein was observed, which was similar in small cell and non-small cell lung tumours; however, nuclear labelling for the kallikreins was absent or limited