Bis (monoacylglycero) phosphate interfacial properties and lipolysis by pancreatic lipase-related protein 2, an enzyme present in THP-1 human monocytes

• Published in: Biochimica et biophysica acta 2011-07, Vol.1811 (7-8), p.419-430
• Main Authors: Record, Michel, Amara, Sawsan, Subra, Caroline, Jiang, Guowei, Prestwich, Glenn D., Ferrato, Francine, Carrière, Frédéric
• Format: Article
• Language: English
• Subjects: Base Sequence; Biophysical Phenomena; Cell Line; DNA, Complementary - genetics; Endosomes - metabolism; enzyme activity; Humans; Hydrogen-Ion Concentration; Hydrolysis; Immunohistochemistry; Lipase; Lipase - genetics; Lipase - metabolism; Lipolysis; Lysophospholipids - chemistry; Lysophospholipids - metabolism; Lysophospholipids - pharmacology; Molecular Structure; monocytes; Monocytes - drug effects; Monocytes - metabolism; Monoglycerides - chemistry; Monoglycerides - metabolism; Monoglycerides - pharmacology; Monomolecular film; phosphates; Phosphatidic Acids - chemistry; Phosphatidic Acids - metabolism; Phosphatidic Acids - pharmacology; Phospholipase A1; Phospholipid; phospholipids; physical properties; PLRP2; pressure; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; surface area; Unilamellar Liposomes - chemistry
• ISSN: 1388-1981; 0006-3002; 1879-2618
• DOI: 10.1016/j.bbalip.2011.04.008

The interfacial physical properties of bis(monoacylglycero)phosphate (BMP) and its derivatives with three oleoyl chains (hemi-BDP) and four oleoyl chains (bis(diacylglycero)phosphate, BDP) were investigated using Langmuir monomolecular films. The mean molecular area of BMP at the collapse surface pressure (45mN m−1) was similar to those measured with other phospholipids bearing two acyl chains (66 and 59.6Å2 molecule−1 at pH 5.5 and 8.0, respectively). In Hemi-BDP and BDP, the mean molecular area increased by 26 and 35Å2 molecule−1 per additional acyl chain at pH 5.5 and 8.0, respectively. When BMP was added to a phospholipid mixture mimicking late endosome membrane composition at pH 8.0, the mean phospholipid molecular area increased by 7% regardless of the surface pressure. In contrast, the variation in molecular area was surface pressure-dependent at pH 5.5, a pH value close to that of intra-endosomal content. BMP and hemi-BDP, but not BDP, were hydrolyzed by pancreatic lipase-related protein 2 (PLRP2), which exhibits phospholipase A1 activity. At pH 5.5, the maximum activities of PLRP2 on BMP were recorded at high surface pressures (25–35mN/m). At pH 8.0, the PLRP2 activity vs. surface pressure showed a bell-shaped curve with maximum activities at 15mN/m for both BMP and hemi-BDP. This is a new activity for this enzyme which could degrade cellular BMP since both human PLRP2 (HPLRP2) and BMP were localized in human monocytic THP-1 cells. This is the first report on the cellular localization of HPLRP2 in human monocytes. ► Interfacial properties of bis (monoacylglycero) phosphate (BMP) and mixed monolayers. ► pH-dependent role of BMP in vesicle formation. ► Phospholipase A1 activity of pancreatic lipase related-protein 2 (PLRP2) on BMP. ► Cellular location of human PLRP2 and BMP in THP-1 monocytes.