title: Hot spot mapping of protein surfaces with TEMPOL: Bovine pancreatic RNase A as a model system.
abstract: TEMPOL spin-label has been used to identify surface exposure of protein nuclei from NMR analysis of the induced paramagnetic relaxation enhancements (PRE). The absence of linear dependence between atom depths and observed PRE reveals that specific mechanisms drive the approach of the paramagnet to the protein surface. RNase A represents a unique protein system to explore the fine details of the information offered by TEMPOL induced PRE, due to the abundance of previous results, obtained in solution and in the crystal, dealing with surface dynamics behavior of this protein. MD simulations in explicit solvent have been performed, also in the presence of TEMPOL, in order to delineate the role of intermolecular hydrogen bonds (HB) on PRE extents. Comparison of our results with the ones obtained from multiple solvent crystal structure (MSCS) studies yields information on the specificities that these two techniques have for characterizing protein-ligand interactions, a fundamental step in the development of reliable surface druggability predictors.
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via A. Moro 2, 53100 Siena, Italy. Electronic address: neri.niccolai@unisi.it.
authors.forename: Neri
authors.initials: N
authors.lastname: Niccolai
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via A. Moro 2, 53100 Siena, Italy. Electronic address: edoardo.morandi@student.unisi.it.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Morandi
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via A. Moro 2, 53100 Siena, Italy. Electronic address: simone.gardini@student.unisi.it.
authors.forename: Simone
authors.initials: S
authors.lastname: Gardini
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via A. Moro 2, 53100 Siena, Italy. Electronic address: valentino.costabile@student.unisi.it.
authors.forename: Valentino
authors.initials: V
authors.lastname: Costabile
authors.affiliation: Dipartimento di Scienze e Tecnologie, Università del Sannio, Via Port'Arsa 11, 82100 Benevento, Italy. Electronic address: rspadacc@unisannio.it.
authors.forename: Roberta
authors.initials: R
authors.lastname: Spadaccini
authors.affiliation: Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80126 Napoli, Italy. Electronic address: orlando.crescenzi@unina.it.
authors.forename: Orlando
authors.initials: O
authors.lastname: Crescenzi
authors.affiliation: Dipartimento di Scienze Chimiche, Università degli Studi di Napoli Federico II, Via Cintia, 80126 Napoli, Italy. Electronic address: delia.picone@unina.it.
authors.forename: Delia
authors.initials: D
authors.lastname: Picone
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via A. Moro 2, 53100 Siena, Italy. Electronic address: ottavia.spiga@unisi.it.
authors.forename: Ottavia
authors.initials: O
authors.lastname: Spiga
authors.affiliation: Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via A. Moro 2, 53100 Siena, Italy. Electronic address: andrea.bernini@unisi.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bernini
mesh_terms: D000818:Animals; D002417:Cattle; D003497:Cyclic N-Oxides / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D006859:Hydrogen / Q000737:chemistry; D006860:Hydrogen Bonding; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008565:Membrane Proteins / Q000737:chemistry; D008954:Models, Biological; D008958:Models, Molecular; D012259:Ribonuclease, Pancreatic / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013113:Spin Labels
chemical_list: D003497:Cyclic N-Oxides; D008024:Ligands; D008565:Membrane Proteins; D012997:Solvents; D013113:Spin Labels; D006859:Hydrogen; D012259:Ribonuclease, Pancreatic; C001803:tempol
keywords: Paramagnetic probes; Protein NMR; Protein hot spots; RNase A; Surface druggability; TEMPOL