Q7M3P9 · HTN_HAEGH
- ProteinHementin
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids
- Protein existenceEvidence at protein level
- Annotation score4/5
Function
function
Metalloprotease with anticoagulant activity. Cleaves fibrinogen Aalpha (FGA), gamma (FGG) and Bbeta (FGB) chains after positions 'Asn-121', 'Lys-160' and 'Pro-102', respectively. Breaks down cross-linked and non-cross-linked fibrin clots. Prevents and reverts platelet aggregation induced by ADP and collagen. Prevents thrombin-induced platelet clotting. Does not affect plasma levels of coagulation factors prothrombin (F2), V (F5), VII (F7), VIII (F8), IX (F9), X (F10), XI (F11), XII (F12), plasma kallikrein (KLKB1) and kininogen-1 (KNG1).
Miscellaneous
Presumably not injected into the host's bloodstream, as feeding by H.ghilianii does not cause prolonged bleeding of resulting wounds.
Cofactor
Activity regulation
Inhibited by EDTA, cysteine, DTT and sodium phosphate. Partially inhibited by EGTA, citrate, Tris and glycine. Not inhibited by DFP, PMSF, iodoacetic acid and leupeptin. Requires sodium chloride concentrations higher than 0.15 M for activity.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
1 μM | fibrinogen |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
26 nmol/min/mg | with fibrinogen as substrate | ||||
2.4 pmol/sec/mg | with cross-linked fibrin clots as substrate (with enzyme incorporated in clot) | ||||
2.6 pmol/sec/mg | with non-cross-linked fibrin clots as substrate (with enzyme incorporated in clot) | ||||
0.011 pmol/sec/mg | with cross-linked fibrin clots as substrate (with enzyme external to clot) | ||||
0.05 pmol/sec/mg | with non-cross-linked fibrin clots as substrate (with enzyme external to clot) |
pH Dependence
Optimum pH is 7.5. Active from pH 5.5 to 11.
Temperature Dependence
Active at 37 degrees Celsius. Activity reversibly reduced to 26% and 0% at 25 degrees Celsius and 4 degrees Celsius, respectively. Complete and irreversible loss of activity after 15 minutes at 60 degrees Celsius.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Molecular Function | metallopeptidase activity | |
Molecular Function | toxin activity | |
Biological Process | proteolysis |
Keywords
- Molecular function
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameHementin
- EC number
Organism names
- Taxonomic lineageEukaryota > Metazoa > Spiralia > Lophotrochozoa > Annelida > Clitellata > Hirudinea > Rhynchobdellida > Glossiphoniidae > Haementeria
Accessions
- Primary accessionQ7M3P9
Subcellular Location
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000397939 | 1-39 | Hementin | |||
Sequence: TTLTEPEPDLTYLTFVXIVXXEMPIFVMATANSGITSTF |
Expression
Tissue specificity
Expressed mainly in the posterior salivary glands and, to a lesser extent, in the anterior salivary glands and secreted into the proboscis (at protein level).
Structure
Family & Domains
Family and domain databases
Sequence
- Sequence statusFragments
- Length39
- Mass (Da)4,286
- Last updated2010-10-05 v2
- Checksum8D6433D2AA549698
Features
Showing features for non-adjacent residues, non-terminal residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Non-adjacent residues | 10-11 | |||||
Sequence: LT | ||||||
Non-terminal residue | 39 | |||||
Sequence: F |
Keywords
- Technical term