Kininogen 1

Kininogen-1 (KNG1), also known as alpha-2-thiol proteinase inhibitor, Williams-Fitzgerald-Flaujeac factor or the HMWK-kallikrein factor is a is_associated_with::protein that in humans is encoded by the KNG1 is_associated_with::gene. Kininogen-1 is the precursor protein to is_associated_with::high-molecular-weight kininogen (HMWK), is_associated_with::low-molecular-weight kininogen (LMWK), and is_associated_with::bradykinin.

Expression
The KNG1 gene uses is_associated_with::alternative splicing to generate two different proteins: is_associated_with::high-molecular-weight kininogen (HMWK) and is_associated_with::low-molecular-weight kininogen (LMWK). HMWK in turn is cleaved by the enzyme is_associated_with::kallikrein to produce is_associated_with::bradykinin.


 * KNG1 gene → is_associated_with::low-molecular-weight kininogen (LMWK) protein (contains 427 amino acids) or is_associated_with::high-molecular-weight kininogen (HMWK) protein (644 amino acids)
 * HMWK protein → is_associated_with::bradykinin peptide (9 amino acids)

Function
HMWK is essential for blood coagulation and assembly of the kallikrein-kinin system. Also, is_associated_with::bradykinin, a peptide causing numerous physiological effects, is released from HMWK. In contrast to HMWK, LMWK is not involved in blood coagulation.

Kininogen-1 is a constituent of the blood coagulation system as well as the is_associated_with::kinin-kallikrein system.