The synergistic action of melittin and phospholipase A2 with lipid membranes: development of linear dichroism for membrane-insertion kinetics.
Here we present data on the kinetics of insertion of melittin, a peptide from bee venom, into lipid membranes of different composition. Another component of bee venom is the enzyme phospholipase A2 (PLA₂). We have examined the interaction of melittin and PLA₂ with liposomes both separately and combined and demonstrate that they work synergistically to disrupt the membranes. A dramatic difference in the action of melittin and PLA₂ is observed when the composition of the membrane is altered. Temperature also has a large effect on the kinetics of insertion and membrane disruption. We use a combination of techniques to measure liposome size (dynamic light scattering), peptide secondary structure (circular dichroism spectroscopy), peptide orientation relative to the membrane (linear dichroism spectroscopy) and enzymatic digestion of the lipids (mass spectrometry).
Damianoglou
Angeliki
A
Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
Rodger
Alison
A
Pridmore
Catherine
C
Dafforn
Timothy R
TR
Mosely
Jackie A
JA
Sanderson
John M
JM
Hicks
Matthew R
MR
D000818:Animals; D001514:Bee Venoms / Q000737:chemistry; D001516:Bees; D020404:Glycerophospholipids / Q000737:chemistry* / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008081:Liposomes / Q000737:chemistry* / Q000378:metabolism; D008555:Melitten / Q000737:chemistry* / Q000378:metabolism; D054467:Phospholipases A2 / Q000737:chemistry* / Q000378:metabolism; D011487:Protein Conformation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013057:Spectrum Analysis / Q000379:methods*; D013696:Temperature
D001514:Bee Venoms; D020404:Glycerophospholipids; D008051:Lipid Bilayers; D008081:Liposomes; D008555:Melitten; D054467:Phospholipases A2