Protection by chlorpromazine, albumin and bivalent cations against haemolysis induced by melittin, [Ala-14]melittin and whole bee venom

Abstract

The ability of the peptides melittin, [Ala-14]melittin (P14A) and whole bee venom to lyse red blood cells (RBC) and to cause shape transformation, binding, partitioning and changes in volume of the cells during haemolysis, as well as the action of the bivalent cations Zn2+ and Ca2+, chlorpromazine, albumin and plasma on the peptide-induced haemolysis of RBC in high ionic-strength solution, have been investigated. The protective effect of all inhibitors depends on whether they have been added to the media before or after the cells. When added before the cells they reduced significantly the rate of peptide-induced haemolysis and shape transformation. The effect was maximal when agents acted simultaneously after introduction of the cells into the media containing both inhibitors and peptides. Incubation of the cells in isotonic solution before the addition of peptides enhanced 2-3-fold the RBC susceptibility (i.e. rate of haemolysis) to lytic action of the same amount of peptides, and increased the order of the haemolytic reaction, although the power law coefficient did not exceed a value of 2 for all peptides, suggesting that haemolysis is attributable to the monomeric or dimeric forms of the peptides. Partition coefficients were of the order of approximately 10(6) M-1, and P14A possessed a value 3-fold larger compared with melittin and bee venom, which correlated with its enhanced haemolytic activity. The protective action of inhibitors against peptide-induced haemolysis has been explained on the basis of their ability to compete with peptide binding at an early stage of peptide-membrane interaction, and not as a result of inhibition of a pre-existing peptide-induced pore. Whereas melittin increased the volume of RBC during haemolysis, P14A, melittin in the presence of phospholipase A2 or bee venom, reduced the volume in a concentration-dependent manner. The present data reveal the significant role of the initial stage of peptide-membrane interaction and peptide structure in the mechanism of haemolysis. These data are not consistent with a lipid-based mechanism of peptide-induced haemolysis, indicating that the mode of peptide-protein interaction is an important and decisive step in the haemolytic mechanism. It should be noted that data (in the form of three additional Tables) on the ability of inhibitors to protect cells from haemolysis when inhibitor and peptide act simultaneously are available. They are reported in Supplementary Publication SUP 50178, which has been deposited at the British Library Document Supply Centre, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1996) 313, 9.

Membrane perturbing properties of natural phenolic and resorcinolic lipids

“…The lysis of cells induced by various compounds can be modulated by the presence of divalent cations the medium. This protective effect been demonstrated for many different lytic agents [17,[23][24][25]. I found that the lysis of erythrocytes induced by investigated lipids from CNSL was also inhibited in the presence of divalent cations ( Fig.…”

Charge distribution and imperfect amphipathicity affect pore formation by antimicrobial peptides

“…It has been reported that substitution of proline 14 by alanine resulted in stronger binding affinity for POPC (1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine) membranes, less efficient leakage of fluorescent markers, different pore formation kinetics and different hemolytic mechanisms [52–54]. These differences have been attributed to structural changes brought about by the mutation.…”

“…Such a structure has not been observed for melittin. Different pore formation kinetics and hemolytic mechanisms, as well as reduced leakage and a slightly reduced hemolytic activity of P14A compared to melittin have been reported in experimental studies [49, 52–54]. …”