UV-POSIT: Web-Based Tools for Rapid and Facile Structural Interpretation of Ultraviolet Photodissociation (UVPD) Mass Spectra

  • Jake Rosenberg
  • W. Ryan Parker
  • Michael B. Cammarata
  • Jennifer S. Brodbelt
Application Note


UV-POSIT (Ultraviolet Photodissociation Online Structure Interrogation Tools) is a suite of web-based tools designed to facilitate the rapid interpretation of data from native mass spectrometry experiments making use of 193 nm ultraviolet photodissociation (UVPD). The suite includes four separate utilities which assist in the calculation of fragment ion abundances as a function of backbone cleavage sites and sequence position; the localization of charge sites in intact proteins; the calculation of hydrogen elimination propensity for a-type fragment ions; and mass-offset searching of UVPD spectra to identify unknown modifications and assess false positive fragment identifications. UV-POSIT is implemented as a Python/Flask web application hosted at UV-POSIT is available under the MIT license, and the source code is available at

Graphical Abstract


Ultraviolet photodissociation Charge site Protein Native MS 



Funding from the NIH (R01GM121714 and 1K12GM102745 (fellowship to MBC)) and the Robert A. Welch Foundation (F-1155) is acknowledged.

Supplementary material

13361_2018_1918_MOESM1_ESM.pdf (428 kb)
ESM 1 (PDF 428 kb)


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Copyright information

© American Society for Mass Spectrometry 2018

Authors and Affiliations

  • Jake Rosenberg
    • 1
  • W. Ryan Parker
    • 1
  • Michael B. Cammarata
    • 1
  • Jennifer S. Brodbelt
    • 1
  1. 1.Department of ChemistryThe University of Texas at AustinAustinUSA

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