Staphylococcal lipases stereoselectively hydrolyse the sn-2 position of monomolecular films of diglyceride analogs. Application to sn-2 hydrolysis of triolein

The enzymic hydrolysis of three synthetic sphingomyelins, spread as monomolecular films at the air/water interface by purified Staphylococcus aureus sphingomyelinase was studied. Each of the three sphinomyelins (DL-erythro-N-palmitoyl-, -N-stearoyl- and -N-lignoceryl-sphingosylphosphocholine) has an optimal activity-dependent surface pressure or concentration curve. The optimal surface pressure as well as the optimal surface density for hydrolysis was different for each of the three substrates. This optimum coincides with the liquid-condensed/liquid-expanded phase transition for each of the sphingomyelins. At initial surface pressures (pi 0) below the optimum, reaction rates are controlled mainly by surface density of the substrate; above the optimal pi 0, reaction rates decrease with increasing surface pressure. The difference between the three synthetic sphingomyelins are explained by the variation in the degree of asymmetry between their two paraffinic chains.

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Hydrolysis of monomolecular films of trioctanoin by porcine pancreatic lipase

Biochemical and Biophysical Research Communications ◽

10.1016/0006-291x(70)90258-5 ◽

1970 ◽

Vol 39 (4) ◽

pp. 672-682 ◽

Cited By ~ 27

Author(s):

Charles W. Garner ◽

Louis C. Smith

Keyword(s):

Pancreatic Lipase ◽

Porcine Pancreatic Lipase ◽

Monomolecular Films ◽

Hydrolysis Of

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The influence of bile salts and bile lipoprotein complex on pancreatic lipase hydrolysis of monomolecular films

Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism ◽

10.1016/0005-2760(80)90058-2 ◽

1980 ◽

Vol 618 (1) ◽

pp. 106-118 ◽

Cited By ~ 25

Author(s):

Denis Lairon ◽

Monique Charbonnier-Augeire ◽

Gilles Nalbone ◽

Jeannie Leonardi ◽

Jaques C. Hauton ◽

...

Keyword(s):

Pancreatic Lipase ◽

Bile Salts ◽

Pancreatic Lipase Hydrolysis ◽

Lipase Hydrolysis ◽

Monomolecular Films ◽

Lipoprotein Complex ◽

Hydrolysis Of

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Surfactant protein B inhibits secretory phospholipase A2 hydrolysis of surfactant phospholipids

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00054.2011 ◽

2012 ◽

Vol 302 (2) ◽

pp. L257-L265 ◽

Cited By ~ 10

Author(s):

R. Duncan Hite ◽

Bonnie L. Grier ◽

B. Moseley Waite ◽

Ruud A. Veldhuizen ◽

Fred Possmayer ◽

...

Keyword(s):

Protein A ◽

Lipid Vesicles ◽

Surfactant Protein ◽

Airway Diseases ◽

Surfactant Protein B ◽

Monomolecular Films ◽

Alveolar Surfactant ◽

Surfactant Phospholipids ◽

Air Liquid Interface ◽

Hydrolysis Of

Hydrolysis of surfactant phospholipids (PL) by secretory phospholipases A2 (sPLA2) contributes to surfactant damage in inflammatory airway diseases such as acute lung injury/acute respiratory distress syndrome. We and others have reported that each sPLA2 exhibits specificity in hydrolyzing different PLs in pulmonary surfactant and that the presence of hydrophilic surfactant protein A (SP-A) alters sPLA2-mediated hydrolysis. This report tests the hypothesis that hydrophobic SP-B also inhibits sPLA2-mediated surfactant hydrolysis. Three surfactant preparations were used containing varied amounts of SP-B and radiolabeled tracers of phosphatidylcholine (PC) or phosphatidylglycerol (PG): 1) washed ovine surfactant (OS) (pre- and postorganic extraction) compared with Survanta (protein poor), 2) Survanta supplemented with purified bovine SP-B (1–5%, wt/wt), and 3) a mixture of dipalmitoylphosphatidylcholine (DPPC), 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC), and 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) (DPPC:POPC:POPG, 40:40:20) prepared as vesicles and monomolecular films in the presence or absence of SP-B. Hydrolysis of PG and PC by Group IB sPLA2 (PLA2G1A) was significantly lower in the extracted OS, which contains SP-B, compared with Survanta ( P = 0.005), which is SP-B poor. Hydrolysis of PG and PC in nonextracted OS, which contains all SPs, was lower than both Survanta and extracted OS. When Survanta was supplemented with 1% SP-B, PG and PC hydrolysis by PLA2G1B was significantly lower ( P < 0.001) than in Survanta alone. When supplemented into pure lipid vesicles and monomolecular films composed of PG and PC mixtures, SP-B also inhibited hydrolysis by both PLA2G1B and Group IIA sPLA2 (PLA2G2A). In films, PLA2G1B hydrolyzed surfactant PL monolayers at surface pressures ≤30 mN/m ( P < 0.01), and SP-B lowered the surface pressure range at which hydrolysis can occur. These results suggest the hydrophobic SP, SP-B, protects alveolar surfactant PL from hydrolysis mediated by multiple sPLA2 in both vesicles (alveolar subphase) and monomolecular films (air-liquid interface).

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