Heparanase

From Anvita Health Wiki

Contents 1 Function 2 Structure 3 Compartment 4 Expression 5 Pathology 6 More General Terms 7 Additional Terms 8 Internet Database 9 References

Function

• endoglycosidase, cell surface & extracellular matrix- degrading enzyme
• cleaves heparan sulfate proteoglycans into heparan sulfate side chains & core proteoglycans
• role in extravasation of leukocytes
• role in angiogenesis
  

• Cofactor: activated by Ca+2 & Mg+2
  
• Inhibition:

• inhibited by EDTA, laminarin sulfate and, to a lesser extent, by heparin & sulfamin
  

• Kinetic parameters:

• Optimum pH is 4-6

Structure

• active heterodimer is composed of the 8 and 50 kD subunits, proteolytic products
• proteolytically processed; cleavage of 65 kD form generate linker peptide, 8 kD & 50 kD peptides
• active form, 8/50 kD heterodimer, is resistant to degradation
• complete removal of linker peptide required for complete activation of enzyme
• N-glycosylated
• glycosylation of the 50 kD subunit essential for solubility
• belongs to the glycosyl hydrolase 79 family

Compartment

• lysosomal membrane; peripheral membrane, secreted
• secreted, internalised & transferred to late endosomes/ lysosomes as proheparanase
• in lysosomes, processed into active form, heparanase
• uptake or internalisation of proheparanase is mediated by heparan sulfate proteoglycans
• heparin inhibits internalization

Expression

• expressed in placenta, spleen > lymph node, thymus, peripheral blood leukocytes, bone marrow, endothelial cells, fetal liver

Pathology

• role in extravasation of tumor cells
• role in metastasis & angiogenesis
• weakly expressed in tumor cells

More General Terms

• glycosidase (glycoside hydrolase)
• membrane protein
• secreted protein

Additional Terms

• heparanase-2 (Hpa2, HPSE2, HPA2)

Internet Database

OMIM: 604724
UniProt: [1]

References

UniProt [2]

heparanase (heparanase-1, Hpa1, endo-glucoronidase, [Contains: Heparanase 8 kD subunit; Heparanase 50 kD subunit], HPSE, HEP, HPA, HPA1, HPR1, HPSE1, HSE1)