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- Wieloch, T., et al.
(författare)
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Product activation of pancreatic lipase. Lipolytic enzymes as probes for lipid/water interfaces
- 1982
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Ingår i: Journal of Biological Chemistry. - 0021-9258. ; 257:19, s. 11523-11528
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Tidskriftsartikel (refereegranskat)abstract
- During the action of pancreatic lipase and colipase on racemic 1,2-didodecanoylglycerol monolayers in the absence of bile salts, biphasic kinetics was observed under conditions of high lipid packing. Similar kinetics has earlier been reported using phospholipid-emulsified triolein droplets. These kinetics are characterized by a lag time τ(d), dependent on products accumulation at the substrate/water interface. This lag time is differentiated from the previously described enzyme concentration independent lag time τ(i) in systems of low lipid packing. Both τ(i) and τ(d) reflect a rate-limiting step due to the slow enzyme penetration into the substrate interface. The variation of τ(d) under different conditions (change in pH and concentration of Ca2+, enzyme, bovine serum albumin, and lipolytic products) lead us to propose a model for the product activation during lipolysis. We will discuss the use of the pancreatic lipase-colipase system to probe the lipid packing of emulsified triglyceride particles and lipoproteins using τ(d) as a reference value.
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