Title : Structure and activity of rat
pancreatic lipase-related protein 2
Abstract :
- The pancreas expresses several members of the lipase gene family including pancreatic triglyceride lipase ( PTL ) and two homologous proteins , pancreatic lipase-related proteins 1 and 2 2 (PLRP1 and PLRP2 )
- Despite their similar amino acid sequences , PTL , PLRP1 , and PLRP2 differ in important kinetic properties
- PLRP1 has no known activity
- PTL and PLRP2 differ in substrate specificity, bile acid inhibition, colipase requirement, and interfacial activation
- To begin understanding the structural explanations for these functional differences, we solved the crystal structure of rat (r) PLRP2 and further characterized its kinetic properties
- The 1.8 A structure of rPLRP2 , like the tertiary structure of human PTL , has a globular N-terminal domain and a beta-sandwich C-terminal domain
- The lid domain occupied the closed position, suggesting that rPLRP2 should show interfacial activation
- When we reexamined this issue with tripropionin as substrate, rPLRP2 exhibited interfacial activation
- Because the active site topology of rPLRP2 resembled that of human PTL , we predicted and demonstrated that the lipase inhibitors E600 and tetrahydrolipstatin inhibit rPLRP2
- Although PTL and rPLRP2 have similar active sites , rPLRP2 has a broader substrate specificity that we confirmed using a monolayer technique
- With this assay, we showed for the first time that rPLRP2 prefers phosphatidylglycerol and ethanolamine over phosphatidylcholine
- In summary, we confirmed and extended the observation that PLRP2 lipases have a broader substrate specificity than PTL , we demonstrated that PLRP2 lipases show interfacial activation, and we solved the first crystal structure of a PLRP2 lipase that contains a lid domain
Output (sent_index, trigger,
protein,
sugar,
site):
- 7. occupied, , -, -, domain
Output(Part-Of) (sent_index,
protein,
site):
- 10. PTL, sites
- 10. rPLRP2, sites
- 12. PLRP2 lipase, domain
- 6. structure of rPLRP2, domain
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):