title: Complete sequencing of anti-vancomycin fab fragment by liquid chromatography-electrospray ion trap mass spectrometry with a combination of database searching and manual interpretation of the MS/MS spectra.
abstract: Sequencing of anti-vancomycin monoclonal antibody (mAb) Fab region (48,000 Da) was carried out using liquid chromatography-electrospray ionization ion trap mass spectrometry (LC/ESI-MS). Comprehensive strategies were employed to ensure complete sequence coverage. The sequence information was obtained from the spectra of collision-induced dissociation (CID) (MS/MS) of the protonated proteolytic peptides resulting from multiple enzymatic digestions of reduced/S-carboxymethylated (RCM) light chain and Fd fragment. Database searching of the spectra against the published immunoglobulin G (IgG) sequences allowed the identification of all the peptides in constant domains as well as partial sequences in variable domains. The rest of the sequences were deduced by manual interpretation of the peptide tandem mass spectrometry (MS/MS) spectra. The analysis showed that the N-terminus of the heavy chain was modified by the conversion of a glutamine residue to pyroglutamic acid.
authors.affiliation: Department of Organic Chemistry (9NM), Abbott Diagnostics Division, Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064-6016, USA. maciej.adamczyk@abbott.com
authors.forename: Maciej
authors.initials: M
authors.lastname: Adamczyk
authors.forename: John C
authors.initials: JC
authors.lastname: Gebler
authors.forename: Jiang
authors.initials: J
authors.lastname: Wu
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Yu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods; D030562:Databases, Protein; D007140:Immunoglobulin Fab Fragments / Q000032:analysis* / Q000235:genetics* / Q000276:immunology; D013058:Mass Spectrometry / Q000379:methods; D051379:Mice; D008969:Molecular Sequence Data; D017421:Sequence Analysis / Q000379:methods*; D014640:Vancomycin / Q000276:immunology
chemical_list: D007140:Immunoglobulin Fab Fragments; D014640:Vancomycin