Ectonucleoside Triphosphate Diphosphohydrolase 8

From Anvita Health Wiki

Contents 1 Function 2 Structure 3 Compartment 4 Alternative-splicing 5 More General Terms 6 Internet Database 7 References

Function

• canalicular ectonucleoside NTPDase responsible for the main hepatic NTPDase activity
• ectonucleoside NTPDases catalyze hydrolyzis of gamma & beta- phosphate residues of nucleotides, playing a role in concentration of extracellular nucleotides
• has activity toward ATP, ADP, UTP & UDP, but not toward AMP
• not inhibited by ARL 67156
  

• Kinetic parameters:

• KM=81 uM for ATP
• KM=137 uM for ADP
• KM=480 uM for UTP
• KM=241 uM for UDP
• Vmax=790 nmol/min/mg enzyme with ATP as substrate
• Vmax=163 nmol/min/mg enzyme with ADP as substrate
• Vmax=1100 nmol/min/mg enzyme with UTP as substrate
• Vmax=110 nmol/min/mg enzyme with UDP as substrate
  

• ATP + 2 H2O <--> AMP + 2 phosphate
  
• Cofactor: Ca+2 ( putative)

Structure

• transmembranous domains are involved in regulation of enzyme activity
• belongs to the GDA1/ CD39 NTPase family
• N-glycosylated

Compartment

• cell membrane

Alternative-splicing

• named isoforms=2

More General Terms

• membrane protein

Internet Database

Prosite: [1]
UniProt: [2]

References

UniProt [3]

ectonucleoside triphosphate diphosphohydrolase 8 (NTPDase 8, NTPDase8, E-NTPDase 8, ENTPD8)