title: Observation of water molecules bound to a protein using cold-spray ionization mass spectrometry.
abstract: The characterization of water molecules bound to ribonuclease T1 (RNase T1) was carried out using cold-spray ionization mass spectrometry (CSI-MS). CSI-MS is a variant of electrospray ionization mass spectrometry (ESI-MS) operating at low temperature, and is particularly suitable for investigating the weaker molecular associations, since the temperature at the spray interface is much lower than that in the conventional ESI-MS. In this approach, ion peaks due to the addition of nine water molecules were identified at a spray temperature of 48 degrees C. This result showed good agreement with that inferred by the combinational analysis of NMR and X-ray crystallography, indicating that CSI-MS is capable of rapidly providing reliable information to characterize the number of water molecules bound to a macromolecule.
authors.affiliation: Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, Shido, Sanuki-city, Kagawa 769-2193, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sei
authors.forename: Sakurako
authors.initials: S
authors.lastname: Shimotakahara
authors.forename: Juri
authors.initials: J
authors.lastname: Ishii
authors.forename: Heisaburo
authors.initials: H
authors.lastname: Shindo
authors.forename: Hiroko
authors.initials: H
authors.lastname: Seki
authors.forename: Kentaro
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Tashiro
mesh_terms: D004926:Escherichia coli / Q000201:enzymology; D011485:Protein Binding; D006163:Ribonuclease T1 / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D006163:Ribonuclease T1