Success Story

May 7, 2019  |  Jola Glotzer

Proteoforms explained

A recent review in Proteomics, co-authored by a CBC Senior Investigator and proteomics expert, Neil Kelleher, NU

Neil Kelleher, Northwestern

Congratulations to Neil Kelleher and his team, NU, for their recent publication in Proteomics, “Identification and Quantification of Proteoforms by Mass Spectrometry.” The review is an excellent introduction to the field, so if you ever wondered what the difference is between the top-down and top-up proteomic analysis, this is your chance to find out. Proteoforms and their families are also explained, and finally the paper discusses the remaining challenges in the field.

Kelleher’s many ties to CBC include his recruitment to NU in 2010 with help from the CBC Recruitment Resources Award. Hence his recognition as a CBC Senior Investigator. Kelleher’s other CBC awards and community contributions are listed below the article. The CBC is proud to have played a role in Kelleher’s recruitment and to have helped support his research over the years.

Publication linked to CBC funding*:

Schaffer LV, Millikin RJ, Miller RM, Anderson LC, Fellers RT, Ge Y, Kelleher NL, LeDuc RD, Liu X, Payne SH, Sun L, Thomas PM, Tucholski T, Wang Z, Wu S, Wu Z, Yu D, Shortreed MR, Smith LM. Identification and Quantification of Proteoforms by Mass Spectrometry. Review. Proteomics. First published: 03 May 2019. (


A proteoform is a defined form of a protein derived from a given gene with a specific amino acid sequence and localized post‐translational modifications. In top‐down proteomic analyses, proteoforms are identified and quantified through mass spectrometric analysis of intact proteins. Recent technological developments have enabled comprehensive proteoform analyses in complex samples, and an increasing number of laboratories are adopting top‐down proteomic workflows. In this review, we outline some recent advances and discuss current challenges and future directions for the field.

The sources of variation resulting in different proteoforms. Different proteoforms arising from the same gene make up a proteoform family. (Source: Proteomics.)

Featured CBC Community member(s):

Neil Kelleher, NU


August 9, 2018
▸ Top-down Proteomics
CBC Senior Investigator, Neil Kelleher, NU, explains the advantages of “top-down” versus “bottom-up” proteomics in early cancer detection and progression

April 25, 2018
▸ Using ‘top-down proteomics,’ CBC Senior Investigator, Neil Kelleher, NU, identifies and precisely measures eleven KRAS oncogene proteoforms found in colon cancer cells

March 28, 2018
▸ New insights into the mechanism of methane metabolism by copper-binding bacteria revealed in a study from the Rosenzweig lab and CBC Senior Investigator, Neil Kelleher, NU

March 26, 2018
▸ New, cell-free protein manufacturing methodology, developed by Michael Jewett’s NU team and supported by CBC funding, could have important implications in biomedicine and beyond

November 23, 2017
▸ CBC’s mission of collaboration embraced through inter-institutional teaching and mentoring. Featuring Northwestern’s Chemistry of Life Processes Institute (CLP) Predoctoral Training Program.

November 13, 2017
▸ New insights into regulation of gene expression: work from the Shilatifard lab (NU) with contributions from two CBC scientists, Neil Kelleher and Jeffrey Savas.

October 5, 2017
▸ CBC Senior Investigator, Neil Kelleher, NU, deciphers molecular assembly of a gut toxin, colibactin

August 5, 2015
▸ Researchers Design First Artificial Ribosome

February 9, 2016
▸ “Clasping” Collaboration
Three CBC Scientists Join Forces to Develop Exceptional-Quality Antibodies Displaying an Unprecedented Mode of Action