Anticoagulant Venom and Mammalian Secreted Phospholipases A₂: Protein- versus Phospholipid-Dependent Mechanism of Action

Biochemistry and physiology of mammalian secreted phospholipases A2.

Phospholipases A(2) (PLA2s) are esterases that hydrolyze the sn-2 ester of glycerophospholipids and constitute one of the largest families of lipid hydrolyzing enzymes. The mammalian genome contains 10 enzymatically active secreted PLA2s (sPLA2s) and two sPLA2-related proteins devoid of lipolytic enzymatic activity. In addition to the well-established functions of one of these enzymes in digest...

Snake venom phospholipases A2. A fluorescence study of their binding to phospholipid vesicles correlation with their anticoagulant activities.

The interaction of snake venom phospholipases A2 with phospholipids has been studied by intrinsic fluorescence. This has been performed in order to understand why some enzymes possess anticoagulant properties while others have no action on blood clotting. We show that phospholipases A2 can be distinguished according to their binding properties to phospholipid vesicles. Strong inhibitors of coag...

Protein Engineering in Structure-Function Studies of Viper's Venom Secreted Phospholipases A2

Inhibitory effects of surfactant protein A on surfactant phospholipid hydrolysis by secreted phospholipases A2.

Hydrolysis of surfactant phospholipids by secreted phospholipases A(2) (sPLA(2)) contributes to surfactant dysfunction in acute respiratory distress syndrome. The present study demonstrates that sPLA(2)-IIA, sPLA(2)-V, and sPLA(2)-X efficiently hydrolyze surfactant phospholipids in vitro. In contrast, sPLA(2)-IIC, -IID, -IIE, and -IIF have no effect. Since purified surfactant protein A (SP-A) h...

Mechanism of action of human activated protein C, a thrombin-dependent anticoagulant enzyme.

Human protein C was purified. and the mechanism of action of activated protein C as an anticoagulant in plasma was studied. Protein C was purified from commercial factor IX concentrate by DEAE-Sephadex and dextran sulfate-Sepharose chromatography and preparative polyacrylamide gel electrophoresis. Purified protein C appeared homogenous at 62.000 mol wt on nonreduced SDS-polyacrylamide gels and....