title: Proton transfer in histidine-tryptophan heterodimers embedded in helium droplets.
abstract: We used cold helium droplets as nano-scale reactors to form and ionize, by electron bombardment and charge transfer, aromatic amino acid heterodimers of histidine with tryptophan, methyl-tryptophan, and indole. The molecular interaction occurring through an N-H···N hydrogen bond leads to a proton transfer from the indole group of tryptophan to the imidazole group of histidine in a radical cationic environment.
authors: Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA.
authors: Bruno
authors: B
authors: Bellina
authors: Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA.
authors: Daniel J
authors: DJ
authors: Merthe
authors: Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089-0484, USA.
authors: Vitaly V
authors: VV
authors: Kresin
mesh_terms: D019281:Dimerization; D004583:Electrons; D006371:Helium / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D006860:Hydrogen Bonding; D007211:Indoles / Q000737:chemistry; D013058:Mass Spectrometry; D008956:Models, Chemical; D011522:Protons; D013696:Temperature; D014364:Tryptophan / Q000031:analogs & derivatives / Q000737:chemistry*
chemical_list: D007211:Indoles; D011522:Protons; D006371:Helium; D006639:Histidine; C028129:tryptophan methyl ester; C030374:indole; D014364:Tryptophan