Reboul_2006_Biochim.Biophys.Acta_1761_4

Reference

Title : Pancreatic lipase and pancreatic lipase-related protein 2, but not pancreatic lipase-related protein 1, hydrolyze retinyl palmitate in physiological conditions - Reboul_2006_Biochim.Biophys.Acta_1761_4
Author(s) : Reboul E , Berton A , Moussa M , Kreuzer C , Crenon I , Borel P
Ref : Biochimica & Biophysica Acta , 1761 :4 , 2006
Abstract :

The major sources of vitamin A in the human diet are retinyl esters (mainly retinyl palmitate) and provitamin A carotenoids. It has been shown that classical pancreatic lipase (PL) is involved in the luminal hydrolysis of retinyl palmitate (RP), but it is not known whether pancreatic lipase-related proteins 1 (PLRP1) and 2 (PLRP2), two other lipases recovered in the human pancreatic juice, are also involved. The aim of this study was to assess whether RP acts a substrate for these lipase-related proteins. Pure horse PL, horse PLRP2 and dog PLRP1 were incubated with RP solubilized in its physiological vehicles, i.e., triglyceride-rich lipid droplets, mixed micelles and vesicles. High performance liquid chromatography (HPLC) was used to assess RP hydrolysis by the free retinol released in the incubation medium. Incubation of RP-containing emulsions with horse PL and colipase resulted in RP hydrolysis (0.051+/-0.01 micromol/min/mg). This hydrolysis was abolished when colipase was not added to the medium. PLRP2 and PLRP1 were unable to hydrolyze RP solubilized in emulsions, regardless of whether colipase was added to the medium. PL hydrolyzed RP solubilized in mixed micelles as well (0.074+/-0.014 micromol/min/mg). Again, this hydrolysis was abolished in the absence of colipase. PLRP2 hydrolyzed RP solubilized in micelles but less efficiently than PL (0.023+/-0.005 micromol/min/mg). Colipase had no effect on this hydrolysis. PLRP1 was unable to hydrolyze RP solubilized in micelles, regardless of whether colipase was present or absent. Both PL and PLRP2 hydrolyzed RP solubilized in a vesicle rich-solution, and a synergic phenomenon between the two lipases was enlighten. Taken together, these results show that (1) PL hydrolyzes RP whether RP is solubilized in emulsions or in mixed micelles, (2) PLRP2 hydrolyzes RP only when RP is solubilized in mixed micelles, and (3) PLRP1 is unable to hydrolyze RP regardless of whether RP is solubilized in emulsions or in mixed micelles.

PubMedSearch : Reboul_2006_Biochim.Biophys.Acta_1761_4
PubMedID: 16497549
Gene_locus related to this paper: human-PNLIP , human-PNLIPRP2

Related information

Substrate Retinol-palmitate
Gene_locus Retinol-palmitate    human-PNLIP    human-PNLIPRP2

Citations formats

Reboul E, Berton A, Moussa M, Kreuzer C, Crenon I, Borel P (2006)
Pancreatic lipase and pancreatic lipase-related protein 2, but not pancreatic lipase-related protein 1, hydrolyze retinyl palmitate in physiological conditions
Biochimica & Biophysica Acta 1761 :4

Reboul E, Berton A, Moussa M, Kreuzer C, Crenon I, Borel P (2006)
Biochimica & Biophysica Acta 1761 :4