Lack of Correlation between Anticoagulant Activity and Phospholipid Hydrolysis by Snake Venom Phospholipases A2

Abstract

SummaryThe anticoagulant effects and the simultaneous plasma phospholipid hydrolysis induced by three purified phospholipases obtained from snake venoms, i.e., the basic, relatively toxic N. nigricollis, the neutral, relatively nontoxic H. haemachatus, and the acidic, relatively nontoxic N. n. atra, have been compared. The N. nigricollis phospholipase has a very strong anticoagulant effect at concentrations which induce relatively low levels of phospholipid hydrolysis in plasma. The H. haemachatus and N. n. atra phospholipases become anticoagulant only at high concentrations, and the associated phospholipid hydrolysis is also very high. It is concluded that, while all phospholipases are likely to inhibit coagulation if used in amounts sufficiently large to deplete plasma of phospholipids, strongly active phospholipases, such as N. nigricollis, interfere nonenzymatically with the clotting process before any appreciable phospholipid hydrolysis is reached.

Phaiodactylipin, a glycosylated heterodimeric phospholipase A2 from the venom of the scorpion Anuroctonus phaiodactylus

“…Human blood samples were drawn using 0.13 m Na/citrate as anticoagulant and centrifuged to obtain platelet rich (PRP) and poor (PPP) plasma, as described by Condrea et al . [13]. The aliquots of PPP were brought to 37 °C, and 0.1 mL of either 10 m m Tris/HCl buffer pH 7.4 (control sample) or 0.1 mL of the same buffer containing pure enzyme, were added and incubated for 60 s. The enzyme concentration for each condition was variable, starting at 2 µg per 0.55 mL.…”

Structural, functional, and bioinformatics studies reveal a new snake venom homologue phospholipase A2 class

“…Additionally, proteins that exhibit a natural amino acid mutation in position 49 and adopt a PLA 2 folding (e.g. Lys49‐PLA 2 s, Arg49‐PLA 2 s, Ser49‐PLA 2 s, Gln49‐PLA 2 s, and Asn49‐PLA 2 s) are also found in these venoms and are responsible for additional or other pharmacological properties such as neurotoxic, myotoxic, anticoagulant, bactericidal, hypotensive, and edema‐inducing activities 18–37. Their ability to exhibit such a diverse spectrum of activities is intriguing since PLA 2 s share significant sequential and structural similarity and since these activities emerge from a single structural scaffold 8…”

Caracterización biológica y acción de inhibidores de una fosfolipasa A2 del veneno de Lachesis muta

“…Actividad específica (%) http://sisbib.unmsm.edu.pe/BVRevistas/biologia/biologiaNEW.htm Una de las diferencias resaltantes de la isoforma aislada en este trabajo con la reportada por Mejia et al (2006) es la presencia del notable efecto anticoagulante, la cual alarga el tiempo de recalcificación del plasma, probablemente por hidrólisis de fosfolípidos, indispensable para que funcione la cascada de coagulación por la vía intrínseca (Bofa et al 1982) esta actividad también esta presente en varias PLA 2 aisladas (Kemparaju et al 1994, Boffa & Boffa 1976, Condrea et al 1981, Teng et al 1984y Prado-Franceschi et al 1998). …”