title: Citraconylation--a simple method for high protein sequence coverage in MALDI-TOF mass spectrometry.
abstract: Lysine epsilon -amino group reacts with citraconic anhydride forming a derivative, which is stable on terms for trypsin cleavage. This modification changes the spectrum of peptides formed by the trypsin action; as the number of trypsin-sensitive sites is reduced, the peptides with higher molecular mass can survive in the digest. The various studies of proteins by MALDI-TOF mass spectrometry are often complicated by the low sequence coverage of the peptide chain. This paper demonstrates that the modification of proteins by citraconylation before trypsin cleavage represents a simple experimental technique, which allows a significant increase of sequence coverage in MALDI-TOF mass spectrometry. This improvement is caused both by change of trypsin fragmentation pattern and by disturbance of the protein's native tertiary structure.
authors.affiliation: Department of Biochemistry and Microbiology, Institute of Chemical Technology, Praha 6, 166 28, Czech Republic.
authors.forename: Vojtech
authors.initials: V
authors.lastname: Kadlík
authors.forename: Martin
authors.initials: M
authors.lastname: Strohalm
authors.forename: Milan
authors.initials: M
authors.lastname: Kodícek
mesh_terms: D002949:Citraconic Anhydrides / Q000737:chemistry*; D008239:Lysine / Q000737:chemistry; D008956:Models, Chemical; D009113:Muramidase / Q000737:chemistry / Q000378:metabolism; D009211:Myoglobin / Q000737:chemistry / Q000378:metabolism; D020539:Sequence Analysis, Protein / Q000379:methods*; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013997:Time Factors; D014357:Trypsin / Q000378:metabolism
chemical_list: D002949:Citraconic Anhydrides; D009211:Myoglobin; D012709:Serum Albumin; D009113:Muramidase; D014357:Trypsin; D008239:Lysine