Melittin is a 26residue polypeptide that is present in bee v

Melittin is a 26-residue polypeptide that is present in bee venom. In monomeric form, it inserts itself into lipid rich cell membranes. Given the following sequence for melittin, explain how the sequence of residues could account for the presence of melittin in membranes. Gly-Ile-Gly-Ala-Val-Leu-Lys-Val-Leu-Thr-Gly-Leu-Pro-Ala-Leu-Ile-Ser-Trp- Ne-Lys-Arg-Lys-Arg-Gln-Gln

Solution

Melittin : It is principal active component of bee venom. It consists of 26 amino acids with sequence GIGAVLKVLTTGLPALISWIKRKRQQ and is a powerful stimulator of phospholipase A2.

Role of Melittin Sequence : Major role for 5 lysine and arginine residues in the melittin chains, the equilibrium between melittin monomer and tetramer in solution is probably affected by six positive charges on monomers.

the mechanism of pore formation of lytic peptides such as melittin from been venom involve binding to membrane surface followed by insertion at bound peptide , membrane composed of zwitterionic lipids not only forms pore but also inhibits pore formation.