Disease:Defects in KNG1 are the cause of high molecular weight kininogen deficiency (HMWK deficiency) [MIM:228960]. HMWK deficiency is an autosomal recessive coagulation defect. Patients with HWMK deficiency do not have a hemorrhagic tendency, but they exhibit abnormal surface-mediated activation of fibrinolysis.,Function:(1) Kininogens are inhibitors of thiol proteases; (2) HMW-kininogen plays an important role in blood coagulation by helping to position optimally prekallikrein and factor XI next to factor XII; (3) HMW-kininogen inhibits the thrombin- and plasmin-induced aggregation of thrombocytes; (4) the active peptide bradykinin that is released from HMW-kininogen shows a variety of physiological effects: (4A) influence in smooth muscle contraction, (4B) induction of hypotension, (4C) natriuresis and diuresis, (4D) decrease in blood glucose level, (4E) it is a mediator of inflammation and causes (4E1) increase in vascular permeability, (4E2) stimulation of nociceptors (4E3) release of other mediators of inflammation (e.g. prostaglandins), (4F) it has a cardioprotective effect (directly via bradykinin action, indirectly via endothelium-derived relaxing factor action); (5) LMW-kininogen inhibits the aggregation of thrombocytes; (6) LMW-kininogen is in contrast to HMW-kininogen not involved in blood clotting.,online information:High molecular weight kininogen entry,polymorphism:The T-kinin peptide is missing residues 378 to 380, probably as a result of a naturally occurring variant. The complete sequence of the T-kinin peptide is therefore ISRPPGFSPFR. This peptide is associated with malignant tumors but not with benign ones.,PTM:Bradykinin is released from kininogen by plasma kallikrein.,PTM:Hydroxylation of Pro-383 occurs prior to the release of bradykinin.,similarity:Contains 3 cystatin domains.,tissue specificity:Plasma. T-kinin is detected in malignant ovarian, colon and breast carcinomas, but not in benign tumors.,
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