Tryptases comprise a family of trypsin-like serine proteases, the peptidase family S1. Tryptases are enzymatically active only as heparin-stabilized tetramers, and they are resistant to all known endogenous proteinase inhibitors. Several tryptase genes are clustered on chromosome 16p13.3. These genes are characterized by several distinct features. They have a highly conserved 3' UTR and contain tandem repeat sequences at the 5' flank and 3' UTR which are thought to play a role in regulation of the mRNA stability. These genes have an intron immediately upstream of the initiator Met codon, which separates the site of transcription initiation from protein coding sequence. This feature is characteristic of tryptases but is unusual in other genes. The alleles of this gene exhibit an unusual amount of sequence variation, such that the alleles were once thought to represent two separate genes, beta II and beta III. Beta tryptases appear to be the main isoenzymes expressed in mast cells, whereas in basophils, alpha-tryptases predominate. Tryptases have been implicated as mediators in the pathogenesis of asthma and other allergic and inflammatory disorders.
Function:
Tryptase is the major neutral protease present in mast cells and is secreted upon the coupled activation-degranulation response of this cell type. Has an immunoprotective role during bacterial infection. Required to efficiently combat K.pneumoniae infection (By similarity).
Subunit:
Homotetramer. The active tetramer is converted to inactive monomers at neutral and acidic pH in the absence of heparin. Low concentrations of inactive monomers become active monomers at pH 6.0 in the presence of heparin. When the concentration of active monomers is higher, they convert to active monomers and then to active tetramers. These monomers are active and functionally distinct from the tetrameric enzyme. In contrast to the hidden active sites in the tetrameric form, the active site of the monomeric form is accessible for macromolecular proteins and inhibitors eg: fibrinogen which is a substrate for the monomeric but not for the tetrameric form. The monomeric form forms a complex with SERPINB6.
Subcellular Location:
Secreted.
Similarity:
Belongs to the peptidase S1 family. Tryptase subfamily.
Contains 1 peptidase S1 domain.
SWISS:
P20231
Gene ID:
64499
Database links:
Entrez Gene: 64499 Human
Omim: 191081 Human
SwissProt: P20231 Human
Unigene: 405479 Human
类胰蛋白酶（Tryptase）广泛分布于呼吸道和胃肠道、皮肤等组织中，主要用于呼吸系统、胃肠道系统疾病和其肿瘤的研究。
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