Recherche

Afficher tous les résultats pour

Accueil

Personne

Thomas Rizzo

À propos
Confidentialité
Mentions légales

Graph Chatbot

Publications associées (100)

Kinetically Trapped Liquid-State Conformers of a Sodiated Model Peptide Observed in the Gas Phase

Thomas Rizzo, Chiara Masellis, Markus Schneider, Carsten Baldauf

We investigate the peptide AcPheAla(5)Lyar(+), a model system for studying helix formation in the gas phase, in order to fully understand the forces that stabilize the helical structure. In particular, we address the question of whether the local fixation ...

2017

Glycosaminoglycan Analysis by Cryogenic Messenger-Tagging IR Spectroscopy Combined with IMS-MS

Thomas Rizzo, Michael Zachary Kamrath, Chiara Masellis, Neelam Khanal

We combine ion mobility spectrometry with cryogenic, messenger-tagging, infrared spectroscopy and mass spectrometry to . identify different isomeric disaccharides of chondroitin sulfate (CS) and heparan sulfate (HS), which are representatives of two major ...

2017

Cryogenic Vibrational Spectroscopy Provides Unique Fingerprints for Glycan Identification

Thomas Rizzo, Michael Zachary Kamrath, Chiara Masellis, Neelam Khanal

The structural characterization of glycans by mass spectrometry is particularly challenging. This is because of the high degree of isomerism in which glycans of the same mass can differ in their stereochemistry, attachment points, and degree of branching. ...

2017

UV and IR Spectroscopy of Cryogenically Cooled, Lanthanide-Containing Ions in the Gas Phase

Thomas Rizzo, Yoshiya Inokuchi

We measure UV and IR spectra in the gas phase for EuOH+, EuCl+, and TbO+ ions, which are produced by an electrospray ionization source and cooled to similar to 10 K in a cold, 22-pole ion trap. The UV photodissociation (UVPD) spectra of these ions show a n ...

American Chemical Society2017

Conformations of prolyl-peptide bonds in the bradykinin 1-5 fragment in solution and in the gas phase

Thomas Rizzo, Liudmila Voronina, Antoine Louis Claude Masson, Michael Zachary Kamrath, Carsten Baldauf

The dynamic nature of intrinsically disordered peptides makes them a challenge to characterize by solution-phase techniques. In order to gain insight into the relation between the disordered state and the environment, we explore the conformational space of ...

Amer Chemical Soc2016

IR-induced conformational isomerization of a helical peptide in a cold ion trap

Thomas Rizzo, Caroline Seaiby, Annette Svendsen, Aleksandra Zabuga

In this work we use laser-induced population transfer techniques to study the conformational isomerization of a helical peptide, Ac-Phe-(Ala)5-LysH+, in a cold ion trap. In one scheme, called IR-UV hole-filling spectroscopy, a single conformation is select ...

American Institute of Physics2016

Infrared Spectroscopy of Mobility-Selected H+-Gly-Pro-Gly-Gly (GPGG)

Thomas Rizzo, Ursula Röthlisberger, Antoine Louis Claude Masson, Michael Zachary Kamrath, Marta Andreia Da Silva Perez

We report the first results from a new instrument capable of acquiring infrared spectra of mobility-selected ions. This demonstration involves using ion mobility to first separate the protonated peptide Gly-Pro-Gly-Gly (GPGG) into two conformational famili ...

2015

Spectroscopic studies of kinetically trapped conformations in the gas phase: the case of triply protonated bradykinin

Thomas Rizzo, Liudmila Voronina

Understanding the relation between the gas-phase structure of biological molecules and their solution-phase structure is important when attempting to use gas-phase techniques to address biologically relevant questions. Directly after electrospray ionizatio ...

Royal Soc Chemistry2015

Solvent Effects on the Encapsulation of Divalent Ions by Benzo-18-Crown-6 and Benzo-15-Crown-5

Thomas Rizzo, Yoshiya Inokuchi

We measure UV photodissociation (UVPD) spectra of cold benzo-15-crown-5 (B15C5) and benzo-18-crown-6 (B18C6) complexes with divalent ions (M2+ = Ca2+, Sr2+, Ba2+, and Mn2+), solvated with an H2O or a CH3OH molecule: M2+·B15C5·H2O, M2+·B15C5·CH3OH, M2+·B18C ...

American Chemical Society2015

Cryogenic Spectroscopy and Quantum Molecular Dynamics Determine the Structure of Cyclic Intermediates Involved in Peptide Sequence Scrambling

Thomas Rizzo, Ursula Röthlisberger, Oleg Aseev, Marta Andreia Da Silva Perez

Collision-induced dissociation (CID) is a key technique used in mass spectrometry-based peptide sequencing. Collisionally activated peptides undergo statistical dissociation, forming a series of backbone fragment ions that reflect their amino acid (AA) seq ...

2015

Conformational Structures of a Decapeptide Validated by First Principles Calculations and Cold Ion Spectroscopy

Oleg Boyarkine, Thomas Rizzo, Natalia Nagornova, Vladimir Kopysov, Robert Benny Gerber

Calculated structures of the two most stable conformers of a protonated decapeptide gramicidin S in the gas phase have been validated by comparing the vibrational spectra, calculat- ed from first- principles and measured in a wide spectral range using infr ...

Wiley-V C H Verlag Gmbh2015

Franck–Condon-like Progressions in Infrared Spectra of Biological Molecules

Thomas Rizzo, Aleksandra Zabuga, Michael Zachary Kamrath

Infrared spectra in the NH stretch region are often used for structure determination of gas-phase biological molecules. Vibrational couplings complicate the structure determination process by giving rise to additional vibrational bands along with the expec ...

American Chemical Society2015

Cryogenic Methods for the Spectroscopy of Large, Biomolecular Ions

Oleg Boyarkine, Thomas Rizzo

Determining the conformation of biological molecules is key for understanding their function. The recent combination of mass spectrometry, cryogenic ion traps, and laser spectroscopy is providing new methods to interrogate individual conformations of pepti ...

Springer2015

Molecular Hydrogen Messengers Can Lead to Structural Infidelity: A Cautionary Tale of Protonated Glycine

Thomas Rizzo, Antoine Louis Claude Masson, Evan Rowland Williams

The effects of tagging protonated glycine with either He or with between 1 and 14 H2 molecules on the infrared photodissociation (IRPD) spectra and the ion structure was investigated. Differences in the IR spectra with either a single He atom or H2 molecul ...

American Institute of Physics2015

Fragmentation mechanism of UV-excited peptides in the gas phase

Oleg Boyarkine, Thomas Rizzo, Aleksandra Zabuga, Michael Zachary Kamrath

We present evidence that following near-UV excitation, protonated tyrosine- or phenylalanine–containing peptides undergo intersystem crossing to produce a triplet species. This pathway competes with direct dissociation from the excited electronic state and ...

American Institute of Physics2014

Microhydration Effects on the Encapsulation of Potassium Ion by Dibenzo-18-Crown-6

Oleg Boyarkine, Thomas Rizzo, Yoshiya Inokuchi

We have measured electronic and conformer-specific vibrational spectra of hydrated dibenzo-18-crown-6 (DB18C6) complexes with potassium ion, K+center dot DB18C6 center dot(H2O)(n) (n = 1-5), in a cold, 22-pole ion trap. We also present for comparison spect ...

American Chemical Society2014

Structural Melting of an Amino Acid Dimer upon Intersystem Crossing

Thomas Rizzo, Ulrich Lorenz

We present a spectroscopic investigation of the excited-state dynamics of the phenylalanine (Phe)/serine (Ser) protonated dimer in the gas phase. Using an ultraviolet (UV) laser pulse, we promote individual isomers to the S1 state and probe their fate with ...

Amer Chemical Soc2014

Accurate bond dissociation energy of water determined by triple-resonance vibrational spectroscopy and ab initio calculations

Oleg Boyarkine, Thomas Rizzo, Pavlo Maksyutenko, Oleg Aseev

Triple-resonance vibrational spectroscopy is used to determine the lowest dissociation energy, D0, for the water isotopologue HD16O as 41 239.7 ± 0.2 cm−1 and to improve D0 for H216O to 41 145.92 ± 0.12 cm−1. Ab initio calculations including systematic bas ...

Elsevier2013

Exploring the Mechanism of IR–UV Double-Resonance for Quantitative Spectroscopy of Protonated Polypeptides and Proteins

Oleg Boyarkine, Thomas Rizzo, Natalia Nagornova

Wiley-VCH Verlag GmbH2013

Laser Spectroscopic Study of Cold Host–Guest Complexes of Crown Ethers in the Gas Phase

Oleg Boyarkine, Thomas Rizzo, Yoshiya Inokuchi

A laser spectroscopic study on the structure and dynamics of cold host–guest inclusion complexes of crown ethers (CEs) with various neutral and ionic species in the gas phase is presented. The complexes with neutral guest species are formed by using supers ...

2013

Page 3 sur 5