title: Synthesis and secondary structure in membranes of the Bcl-2 anti-apoptotic domain BH4.
abstract: Solid phase synthesis of BH4, the 26 amino-acid domain (6RTGYDNREIVMKYIHYKLSQRGYEWD31) of the anti-apoptotic Bcl-2 protein has been accomplished using Fmoc chemistry. The use of peculiar cleavage conditions provided high yields after purification such that tens to hundreds of mg could be obtained. A 15N-labelled version of the peptide could also be synthesized for NMR studies in membranes. The peptide purity was not lower than 98% as controlled by UV and MALDI-TOF mass spectrometry. The secondary structure was determined in water, trifluoroethanol (TFE) and in lipid membrane using UV circular dichroism. The peptide shows dominant beta-sheeted structures in water that convert progressively into alpha-helical features upon addition of TFE or membrane. The amphipathic character of the helix suggests that the peptide might have a structure akin to those of antimicrobial peptides upon interaction with membranes.
authors.affiliation: UMR 5144 MOBIOS, CNRS-Université Bordeaux 1, IECB, 33607 Pessac Cedex, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Khemtémourian
authors.forename: Marc-Antoine
authors.initials: MA
authors.lastname: Sani
authors.forename: Katell
authors.initials: K
authors.lastname: Bathany
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gröbner
authors.forename: Erick J
authors.initials: EJ
authors.lastname: Dufourc
mesh_terms: D002942:Circular Dichroism; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008567:Membranes, Artificial; D010715:Phosphatidylglycerols / Q000737:chemistry; D015202:Protein Engineering / Q000379:methods; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000138:chemical synthesis* / Q000737:chemistry* / Q000302:isolation & purification; D012997:Solvents / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D008567:Membranes, Artificial; D010715:Phosphatidylglycerols; D019253:Proto-Oncogene Proteins c-bcl-2; D012997:Solvents; C002773:dimyristoylphosphatidylglycerol; D004134:Dimyristoylphosphatidylcholine