1. In-gel protein digestion using acidic methanol produces a highly selective methylation of glutamic acid residues.
- Author
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Lozano-Prieto M, Camafeita E, Jorge I, Laguillo-Gómez A, Barrero-Rodríguez R, Devesa CA, Pertusa C, Calvo E, Sánchez-Madrid F, Vázquez J, and Martin-Cofreces NB
- Subjects
- Methylation, Humans, Protein Processing, Post-Translational, Proteomics methods, Animals, Methanol chemistry, Glutamic Acid metabolism
- Abstract
Mass-tolerant open search methods allow the high-throughput analysis of modified peptides by mass spectrometry. These techniques have paved the way to unbiased analysis of post-translational modifications in biological contexts, as well as of chemical modifications produced during the manipulation of protein samples. In this work, we have analyzed in-depth a wide variety of samples of different biological origin, including cells, extracellular vesicles, secretomes, centrosomes and tissue preparations, using Comet-ReCom, a recently improved version of the open search engine Comet-PTM. Our results demonstrate that glutamic acid residues undergo intensive methyl esterification when protein digestion is performed using in-gel techniques, but not using gel-free approaches. This effect was highly specific to Glu and was not found for other methylable residues such as Asp., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2024
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