(1) The resulting dimer forms an ion channel in lipid membranes that is selective for monovalent cations only.(2) One explanation is the metal ions bind inside the dimer between the monomers of a double-helix.(3) In this paper, we synthesized a covalent dimer of alamethicin that was N-terminally linked by a disulfide bond.(4) Previous work has shown that these polymerised forms are unstable in acid conditions (such as gastric juice) and that only monomeric, dimeric and trimeric forms are passed to the intestine for absorption.(5) The derived molecular weights were consistent with dimeric or trimeric peptide.(6) There was a previous radiation study of ricin, a dimeric molecule linked by a single disulfide bridge.(7) Molecular dimers are assumed to be not directly degraded.(8) The reactions were followed spectrophotometrically at 300 nm, where the dimeric products of phenol coupling absorb.(9) Furthermore, there was no evidence of ethyl esters, dimers , alkanes or alkenes, which might be expected for an oxidative reaction.(10) In all cases the monomeric lipid molecule is virtually absent, dimeric or trimeric species predominating in each case.
