{"entity": "publication", "iuid": "0e3fa0fff1be4444818e571b700d2dd2", "timestamp": "2026-09-28T11:17:36.269Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/0e3fa0fff1be4444818e571b700d2dd2.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/0e3fa0fff1be4444818e571b700d2dd2"}}, "title": "Gas-Phase Collisions with Trimethylamine-N-Oxide Enable Activation-Controlled Protein Ion Charge Reduction.", "authors": [{"family": "Kaldm\u00e4e", "given": "Margit", "initials": "M"}, {"family": "\u00d6sterlund", "given": "Nicklas", "initials": "N"}, {"family": "Lianoudaki", "given": "Danai", "initials": "D"}, {"family": "Sahin", "given": "Cagla", "initials": "C"}, {"family": "Bergman", "given": "Peter", "initials": "P"}, {"family": "Nyman", "given": "Tomas", "initials": "T"}, {"family": "Kronqvist", "given": "Nina", "initials": "N"}, {"family": "Ilag", "given": "Leopold L", "initials": "LL"}, {"family": "Allison", "given": "Timothy M", "initials": "TM"}, {"family": "Marklund", "given": "Erik G", "initials": "EG"}, {"family": "Landreh", "given": "Michael", "initials": "M"}], "type": "journal article", "published": "2019-08-00", "journal": {"title": "J. Am. Soc. Mass Spectrom.", "issn": "1879-1123", "volume": "30", "issue": "8", "pages": "1385-1388", "issn-l": "1044-0305"}, "abstract": "Modulating protein ion charge is a useful tool for the study of protein folding and interactions by electrospray ionization mass spectrometry. Here, we investigate activation-dependent charge reduction of protein ions with the chemical chaperone trimethylamine-N-oxide (TMAO). Based on experiments carried out on proteins ranging from 4.5 to 35 kDa, we find that when combined with collisional activation, TMAO removes approximately 60% of the charges acquired under native conditions. Ion mobility measurements furthermore show that TMAO-mediated charge reduction produces the same end charge state and arrival time distributions for native-like and denatured protein ions. Our results suggest that gas-phase collisions between the protein ions and TMAO result in proton transfer, in line with previous findings for dimethyl- and trimethylamine. By adjusting the energy of the collisions experienced by the ions, it is possible to control the degree of charge reduction, making TMAO a highly dynamic charge reducer that opens new avenues for manipulating protein charge states in ESI-MS and for investigating the relationship between protein charge and conformation. \u115f.", "doi": "10.1007/s13361-019-02177-8", "pmid": "31286443", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC6669196"}, {"db": "pii", "key": "10.1007/s13361-019-02177-8"}], "notes": [], "created": "2026-09-23T11:46:44.731Z", "modified": "2026-09-23T11:46:44.763Z"}