Matrix assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) of intact proteins is mostly performed using time-of-flight (TOF) based mass spectrometers, operated in linear mode. Linear MALDI-TOF systems provide limited mass resolving power and mass accuracy, which complicates assigning identities to the peaks in the MSI datasets. In this work we report ultra-high mass resolution MALDI-MSI based on 15T Fourier transform ion cyclotron resonance (FTICR) mass spectrometry for the analysis of intact proteins directly from non-embedded and OCT-embedded mouse and human (control and type 2 diabetes) pancreas so that small endocrine compartments (islets of Langerhans) may be analyzed in control and pathological tissues. Sample preparation methods, in terms of increased sensitivity while limiting lateral diffusion of analytes, have been investigated. By combining protein localization, high mass accuracy, and the clearly resolved isotope patterns we were able to assign protein identities with additional confidence, including proteins of similar average mass and with interspersed isotopomers. These capabilities allowed us to ascertain the presence of many protein adducts that, with a low resolving power instrument, could be misinterpreted as distinct protein ions.

Ultra-high resolution MALDI-FTICR-MSI analysis of intact proteins in mouse and human pancreas tissue

Piga, I.
Primo
Methodology
;
Giusti, L.
Supervision
;
Marselli, L.
Membro del Collaboration Group
;
Marchetti, P.
Supervision
;
Mazzoni, M. R.
Supervision
;
Lucacchini, A.
Supervision
;
2019-01-01

Abstract

Matrix assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) of intact proteins is mostly performed using time-of-flight (TOF) based mass spectrometers, operated in linear mode. Linear MALDI-TOF systems provide limited mass resolving power and mass accuracy, which complicates assigning identities to the peaks in the MSI datasets. In this work we report ultra-high mass resolution MALDI-MSI based on 15T Fourier transform ion cyclotron resonance (FTICR) mass spectrometry for the analysis of intact proteins directly from non-embedded and OCT-embedded mouse and human (control and type 2 diabetes) pancreas so that small endocrine compartments (islets of Langerhans) may be analyzed in control and pathological tissues. Sample preparation methods, in terms of increased sensitivity while limiting lateral diffusion of analytes, have been investigated. By combining protein localization, high mass accuracy, and the clearly resolved isotope patterns we were able to assign protein identities with additional confidence, including proteins of similar average mass and with interspersed isotopomers. These capabilities allowed us to ascertain the presence of many protein adducts that, with a low resolving power instrument, could be misinterpreted as distinct protein ions.
2019
Piga, I.; Heijs, B.; Nicolardi, S; Giusti, L.; Marselli, L.; Marchetti, P.; Mazzoni, M. R.; Lucacchini, A.; Mcdonnell, L. A.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/890287
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 23
  • ???jsp.display-item.citation.isi??? 22
social impact