The membrane-proximal tryptophan-rich region of the HIV glycoprotein, gp41, forms a well-defined helix in dodecylphosphocholine micelles.

摘要: The membrane-proximal tryptophan-rich region of the HIV transmembrane glycoprotein, gp41, plays an important role in membrane fusion reaction. Using NMR spectroscopy, we have studied tertiary structure a synthetic 19-residue amidated peptide (NH 2-KWASLWNWFNITNWLWYIK- CONH2) corresponding to this membrane-mimetic environments. Initial experiments sodium dodecyl sulfate/H2O micelles and trifluoroethanol gave poor results, because low solubility. However, dodecylphosphocholine micelles, obtained excellent 500 800 MHz spectra, suggesting that has preference for zwitterionic membrane-like environment. final structures demonstrated well-defined helical with backbone rmsd 0.47 ( 0.18 A. Four five tryptophan residues, as well tyrosine residue, formed "collar" aromatic residues along axial length helix. By analogy related antimicrobial peptides, indicates are positioned within membrane-water interface phospholipid bilayer. This is confirmed by observation direct NOEs between headgroup interfacial protons prototonated dodecylphosphocholine. bulk polar on one face structure, hydrophobic phenylalanine side chain opposing face, forming amphipathic structure. work shows Trp-rich membrane- proximal viruses can bind surfaces zwitterioninc membranes "Velcro-like" manner.