- Protein Z
protein
Name = protein Z
caption =
width =
HGNCid = 9460
Symbol = PROZ
AltSymbols =
EntrezGene = 8858
OMIM = 176895
RefSeq = NM_003891
UniProt = P22891
PDB =
ECnumber =
Chromosome = 13
Arm = q
Band = 34
LocusSupplementaryData =Protein Z is a member of the coagulation cascade, the group of blood proteins that leads to the formation of
blood clot s. It isvitamin K -dependent, and its functionality is therefore impaired inwarfarin therapy. It is aglycoprotein .Physiology
Although it is not enzymatically active, it is structurally related to several
serine protease s of the coagulation cascade: factors VII, IX, X andprotein C . The carboxyglutamate residues (which require vitamin K) bind protein Z tophospholipid surfaces.The main role of protein Z appears to be the degradation of
factor Xa . This is done byprotein Z-related protease inhibitor (ZPI), but the reaction is accelerated 1000-fold by the presence of protein Z. Oddly, ZPI also degradesfactor XI , but this reaction does not require the presence of protein Z.In some studies, deficiency states have been associated with a propensity to
thrombosis . Others, however, link it to bleeding tendency; there is no clear explanation for this, as it acts physiologically as an inhibitor, and deficiency would logically have led to a predisposition forthrombosis .Genetics
It is 62
kDa large and 396amino acid s long. The "PROZ"gene has been linked to the thirteenthchromosome (13q34).It has four domains: a gla-rich region, two EGF-like domains and a trypsin-like domain. It lacks the
serine residue that would make it catalytically active as aserine protease .History
Protein Z was first isolated in
cattle blood by Prowse and Esnouf in 1977, [Prowse CV, Esnouf MP. "The isolation of a new warfarin-sensitive protein from bovine plasma." Biochem Soc Trans 1977;5:255-256. PMID 892175.] and Broze & Miletich determined it in human plasma in 1984. [Broze GJ Jr, Miletich JP. "Human Protein Z." J Clin Invest 1984;73:933-8. PMID 6707212.]References
External links
* [http://www.hprd.org/protein/07182 Human Protein Reference Database]
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