title: Transformation of gas-phase amino acid clusters to dipeptides: a nice approach to demonstrate the formation of prebiotic peptides.
abstract: BACKGROUND
  Exploring prebiotic developments is a fascinating area of research which is continually drawing the attention of the scientific community. It is probable that first the biomolecules were formed and then they became aggregated to generate life. Formation of one such biomolecules (peptide ions) is shown in the present experiments.
  
  
  METHODS
  All amino acid solutions for recording mass spectra were prepared in 3:6.9:0.1 (v/v/v) acetonitrile/water/formic acid at a concentration of 50 μM. The studies were performed using a Bruker MicroTOF QII mass spectrometer. Before carrying out experiments in the collision cell, atmospheric pressure in-source fragmentations were also performed. The formation of different chemical species was detected with high-resolution mass spectrometry.
  
  
  RESULTS
  Here, we show experimentally the formation of amino acid cluster ions of varied populations, when a solution of an amino acid was injected into an electrospray ionization quadrupole time-of-flight (ESI-QTOF) mass spectrometer. During in-source fragmentation/collision cell fragmentation, the non-covalent interaction between two identical amino acids forms either the [M2 + H](+) dimer cluster ion and/or the [M2 + K](+) adduct ion which, by elimination of one molecule of water, form the covalent linked dipeptide.
  
  
  CONCLUSIONS
  After the formation of the amino acid cluster, it was established that the creation of the dipeptides, by a covalent bond resulting from the loss of a water molecule, was the initial step towards the formation of the primordial peptides.
authors.affiliation: Department of Chemistry, UGC Sponsored Centre for Advanced Studies, Guru Nanak Dev University, Amritsar, 143005, India.
authors.forename: Amrinder
authors.initials: A
authors.lastname: Singh
authors.forename: Sukhmeet
authors.initials: S
authors.lastname: Kaur
authors.forename: Jagroop
authors.initials: J
authors.lastname: Kaur
authors.forename: Palwinder
authors.initials: P
authors.lastname: Singh
mesh_terms: D000596:Amino Acids / Q000737:chemistry* / Q000378:metabolism*; D004151:Dipeptides / Q000737:chemistry* / Q000378:metabolism*; D005740:Gases / Q000737:chemistry / Q000378:metabolism; D013058:Mass Spectrometry; D008958:Models, Molecular; D056692:Prebiotics
chemical_list: D000596:Amino Acids; D004151:Dipeptides; D005740:Gases; D056692:Prebiotics