Species Human Entrez 7035 | Human Mouse Ensembl ENSG00000003436 | |
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Aliases TFPI, EPI, LACI, TFI, TFPI1, tissue factor pathway inhibitor External IDs OMIM: 152310 MGI: 1095418 HomoloGene: 4579 GeneCards: TFPI | ||
Tissue factor pathway inhibitor (or TFPI) is a single-chain polypeptide which can reversibly inhibit Factor Xa (Xa). While Xa is inhibited, the Xa-TFPI complex can subsequently also inhibit the FVIIa-tissue factor complex. TFPI contributes significantly to the inhibition of Xa in vivo, despite being present at concentrations of only 2.5 nM.
Contents
Genetics
The gene for TFPI is located on chromosome 2q31-q32.1, and has nine exons which span 70 kb. The gene has not been completely sequenced yet. A similar gene, termed TFPI2, has been identified on chromosome 7q22; in addition to TFPI activity, its product also has retinal pigment epithelial cell growth-promoting properties.
Protein structure
TFPI has a relative molecular mass of 34,000 to 40,000 depending on the degree of proteolysis of the C-terminal region.
TFPI consists of a highly negatively charged amino-terminus, three tandemly linked Kunitz domains, and a highly positively charged carboxy-terminus. With its Kunitz domains, TFPI exhibits significant homology with human inter-alpha-trypsin inhibitor and bovine basic pancreatic trypsin inhibitor.
Interactions
Tissue factor pathway inhibitor has been shown to interact with Factor X.