title: Molecular recognition of N-protected dipeptides by pseudopeptidic macrocycles: a comparative study of the supramolecular complexes by ESI-MS and NMR.
abstract: The molecular recognition properties of pseudopeptidic macrocycles have been studied by ESI-MS and NMR spectroscopy, as highly complementary experimental techniques in solution and in the gas phase. We used ESI-MS competition experiments for the high throughput screening of the supramolecular interaction between four macrocyclic receptors and different peptide-like substrates in solution, rendering the best-fitted host-guest pairs. Further insights on the non-covalent recognition process in the gas-phase were obtained through collision induced dissociation (CID) experiments. Solution studies using NMR spectroscopy ((1)H NMR titrations, NOESY and DOSY) were carried out to prove the validity of ESI-MS as a high-throughput screening method for studying the molecular recognition of the investigated pseudopeptidic macrocycles. A clear selectivity for N-protected dipeptides over N-protected amino acids, and a slight preference for dipeptides bearing aromatic side chains were observed. On the basis of the results obtained from this approach, a mode of binding has been proposed.
authors.affiliation: Departamento de Química Biológica y Modelización Molecular, Instituto de Química Avanzada de Cataluña, Consejo Superior de Investigaciones Científicas, IQAC/CSIC, C/Jordi Girona18-26, E-08034, Barcelona, Spain. ignacio.alfonso@iqac.csic.es
authors.forename: Ignacio
authors.initials: I
authors.lastname: Alfonso
authors.forename: Michael
authors.initials: M
authors.lastname: Bolte
authors.forename: Miriam
authors.initials: M
authors.lastname: Bru
authors.forename: M Isabel
authors.initials: MI
authors.lastname: Burguete
authors.forename: Santiago V
authors.initials: SV
authors.lastname: Luis
authors.forename: Cristian
authors.initials: C
authors.lastname: Vicent
mesh_terms: D000577:Amides / Q000737:chemistry; D004151:Dipeptides / Q000737:chemistry* / Q000378:metabolism*; D005740:Gases / Q000737:chemistry; D047028:Macrocyclic Compounds / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D055550:Protein Stability; D012996:Solutions; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D000577:Amides; D004151:Dipeptides; D005740:Gases; D047028:Macrocyclic Compounds; D012996:Solutions; D009584:Nitrogen