Plasma kallikrein

Plasma kallikrein (EC 3.4.21.34) is an enzyme^{[5][6][7][8][9]} that catalyses the following chemical reaction:

Selective cleavage of some Arg- and Lys- bonds, including Lys-Arg and Arg-Ser in (human) kininogen to release bradykinin

Plasma kallikrein
Identifiers
EC no.	3.4.21.34
CAS no.	410538-33-9
Alt. names	serum kallikrein, kininogenin, kallikrein I, kallikrein II, kininogenase, kallikrein, callicrein, glumorin, padreatin, padutin, kallidinogenase, bradykininogenase, panceatic kallikrein, onokrein P, dilminal D, depot-Padutin, urokallikrein, urinary kallikrein
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

KLKB1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 4OGY, 2ANW, 4OGX, 4ZJ4, 2ANY, 4ZJ5, 4ZJ6
Identifiers
Aliases	KLKB1, KLK3, PPK, PKKD, PKK, kallikrein B1
External IDs	OMIM: 229000; MGI: 102849; HomoloGene: 68097; GeneCards: KLKB1; OMA:KLKB1 - orthologs
Gene location (Human) Chr. Chromosome 4 (human)[1] Band 4q35.2 Start 186,208,979 bp[1] End 186,258,471 bp[1]
Gene location (Mouse) Chr. Chromosome 8 (mouse)[2] Band 8 B1.1|8 25.17 cM Start 45,719,726 bp[2] End 45,747,896 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in right lobe of liver gonad tendon of biceps brachii body of pancreas testicle pancreatic epithelial cell jejunal mucosa dorsal motor nucleus of vagus nerve middle temporal gyrus Epithelium of choroid plexus Top expressed in left lobe of liver right lobe of liver spermatid sexually immature organism neural layer of retina epithelium of lens right kidney respiratory epithelium nose nasal epithelium More reference expression data BioGPS More reference expression data
Gene ontology Molecular function serine-type peptidase activity serine-type endopeptidase activity peptidase activity protein binding hydrolase activity Cellular component extracellular exosome plasma membrane extracellular region extracellular space Biological process positive regulation of fibrinolysis zymogen activation Factor XII activation proteolysis fibrinolysis plasminogen activation extracellular matrix disassembly inflammatory response hemostasis blood coagulation blood coagulation, intrinsic pathway Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3818 16621 Ensembl ENSG00000164344 ENSMUSG00000109764 UniProt P03952 P26262 RefSeq (mRNA) NM_000892 NM_001318394 NM_001318396 NM_008455 RefSeq (protein) NP_000883 NP_001305323 NP_001305325 NP_032481 Location (UCSC) Chr 4: 186.21 – 186.26 Mb Chr 8: 45.72 – 45.75 Mb PubMed search [3] [4]
Wikidata
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Plasma kallikrein and its precursor are encoded by the KLKB1 gene.^[10][11]

This enzyme is formed from prekallikrein (Fletcher factor) by factor XIIa.

Function

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 disulfide 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.^[12]

Interactions

Kallikrein and prekallikrein have been shown to interact with High-molecular-weight kininogen.^{[13][14][15][16]}

See also

• PA clan of proteases