Treasure hunt for peptides with undefined chemical modifications: Proteomics identification of differential albumin adducts of 2 ‐nitroimidazole‐indocyanine green in hypoxic tumor

In this study, we deployed a biotin conjugate of 2‐nitroimidazole‐indocyanine green (2‐nitro‐ICG) for the investigation ofin vivo hypoxia ‐probing mechanism of 2‐nitro‐ICG compounds. By implementing mass spectrometry‐based proteomics and exhaustive data‐mining, we report that 2‐nitro‐ICG and its fragments modify mouse serum albumin as the primary protein target, but at two structurally‐distinct sites and possibly via t wo different mechanisms. The identification of probe‐modified peptides not only contributes to the understanding of thein vivo metabolism of 2 ‐nitroimidazole compounds but also demonstrates a competent analytical workflow that enables the search for peptides with undefined modifications in complex proteome digests.

Source: Journal of Mass Spectrometry - May 24, 2019 Category: Chemistry Authors: Lei Wang, Christopher Dietz, Feifei Zhou, Mohsen Erfanzadeh, Quing Zhu, Michael B. Smith, Xudong Yao Tags: RESEARCH ARTICLE Source Type: research