Conformational change of mastoparan from wasp venom on binding with phospholipid membrane

Abstract

The conformational change upon binding with phospholipid membrane has been studied of mastoparan from wasp venom, a tetradecapeptide causing the degranulation of mast cells. The 270-MHz 'H-NMR spectra and CD spectra indicate that the mastoparan molecule takes the w-helical conformation in methanol solution, but a much less ordered form in aqueous solution. On binding with phospholipid membrane, the m-helical conformation is formed even in aqueous medium. Such a conformational change is primarily due to the interaction between the aliphatic side chains of mastoparan and the hydrophobic interior of phospholipid membrane, in contrast to the case of melittin from bee venom. Circuiar dichroism Co~formational change Peptide-phospho~ipid interaction 'H-NMR ~astoparan Venom peptide

NMR and circular dichroism studies of synthetic peptides derived from the third intracellular loop of the β‐adrenoceptor

“…Similar results were obtained in 10 mM lyso-PC which lead to 50% a-helix. In contrast to T284-295, the wasp venom mastoparan which directly interacts with G proteins shows a complete a-helix in the presence of 10 mM lyso-PC [25]. We propose from the CD spectra that the helical part of the receptor derived peptide T284-295 is probably associated with the phospholipid micelles, whereas the rest of the peptide is flexible like a random chain.…”

Mastoparan inhibits phosphoinositide hydrolysis via pertussis toxin‐intensive G‐protein in human astrocytoma cells

“…They proposed a possibility that mastoparan interacts with polyphosphoinositides to inhibit their hydrolysis. In fact, mastoparan potently interacts with phospholipids [19]. However, mastoparan stimulates phosphoinositide hydrolysis in mast cells, possibly by activating an IAP-sensitive G-protein [6].…”

Physiological activities of peptides are correlated with the conformations of membrane‐bound molecules

“…Egg yolk phosphatidylcholine and lysophosphatidylcholine were prepated as in [8]. L-cu-Phosphatidyl-L-serine from bovine brain was purchased from Nakarai Chemicals and was purified with CM-52 cellulose column chromatography [9].…”