Kininogens are precursor proteins for kinins, biologically active polypeptides involved in blood coagulation, vasodilation, smooth muscle contraction, inflammatory regulation, and the regulation of the cardiovascular and renal systems. There are two main types of kininogen (KNG), high-molecular-weight-kininogen and low-molecular-weight-kininogen, with a third type – T-kininogen – only found in rats but not humans. High-molecular-weight-kininogen (HK) is a non-enzymatic cofactor involved in the kinin-kallikrein system, which plays a role in blood coagulation, blood pressure regulation, and inflammation. It is synthesized in endothelial cells and is produced mostly by the liver. It is also a precursor protein for bradykinin. During the contact activation system (CAS), also known as the intrinsic pathway, the binding of HK, factor XII (FXII), and prekallikrein (PK) to an anionic surface initiates blood coagulation and the kinin-kallikrein system through the activation of a cascade of enzymes. Here you can see a beautiful structure of kininogen bound to coagulation Factor XIa, determined by low resolution X-ray diffraction (PDB code: 7QOT)
#molecularart ... #immolecular ... #coagulation ... #kininogen ... #FactorXIa ... #xray ... #interaction
Structure rendered with @proteinimaging and depicted with @corelphotopaint
#molecularart ... #immolecular ... #coagulation ... #kininogen ... #FactorXIa ... #xray ... #interaction
Structure rendered with @proteinimaging and depicted with @corelphotopaint
