Hydrolysis of DMPC or DPPC by pancreatic phospholipase A2 is slowed down when (perfluoroalkyl) alkanes are incorporated into the liposomal membrane.
The effect of the incorporation of linear (perfluoroalkyl)alkanes (CmF2m + 1CnH2n + 1, FmHn) into liposomes made of DMPC or DPPC on the activity of porcine pancreatic phospholipase A2 was investigated. A large decrease in enzyme activity and modifications of the kinetic profile, especially at and above the phospholipid's phase transition temperature, were observed; both depend on the relative lengths of the phospholipid's fatty acid chains and of the Hn segment of the FmHn molecule. With DMPC Hn must have a minimum of 10 carbon atoms to be effective, as in F6H10, F8H10 and F4H12; F8H8 had no significant hydrolysis-rate-reducing effect. With DPPC Hn must have a minimum of 12 carbon atoms, as in F4H12, while F8H8, F6H10 and F8H10 were ineffective. The absence of effect when C10H22 or C16H34 was incorporated establishes that the fluorinated segment, although its length (from C4 to C8) is not crucial, is required to hinder hydrolysis by PLA2, indicating that this segment plays an important role in structuring the liposomal membrane.
Privitera
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Laboratoire de Chimie Moléculaire, URA 426, Université de Nice Sophia-Antipolis, France.
Naon
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Riess
J G
JG
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry / Q000378:metabolism*; D000473:Alkanes / Q000737:chemistry; D000818:Animals; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D006868:Hydrolysis; D007700:Kinetics; D008081:Liposomes; D010179:Pancreas / Q000201:enzymology; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D013552:Swine
D000473:Alkanes; D008081:Liposomes; D015060:1,2-Dipalmitoylphosphatidylcholine; D010741:Phospholipases A; D054467:Phospholipases A2; D004134:Dimyristoylphosphatidylcholine