title: High-sensitivity TFA-free LC-MS for profiling histones.
abstract: The analysis of proteins by RPLC commonly involves the use of TFA as an ion-pairing agent, even though it forms adducts and suppresses sensitivity. The presence of adducts can complicate protein molecular weight assignment especially when protein isoforms coelute as in the case of histones. To mitigate the complicating effects of TFA adducts in protein LC-MS, we have optimized TFA-free methods for protein separation. Protein standards and histones were used to evaluate TFA-free separations using capillary (0.3 mm id) and nanoscale (0.1 mm id) C(8) columns with the ion-pairing agents, formic acid or acetic acid. The optimized method was then used to examine the applicability of the approach for histone characterization in human cancer cell lines and primary tumor cells from chronic lymphocytic leukemia patients.
authors.affiliation: Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Jia
authors.initials: J
authors.lastname: You
authors.forename: Liwen
authors.initials: L
authors.lastname: Wang
authors.forename: Motoyasu
authors.initials: M
authors.lastname: Saji
authors.forename: Susan V
authors.initials: SV
authors.lastname: Olesik
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Ringel
authors.forename: David M
authors.initials: DM
authors.lastname: Lucas
authors.forename: John C
authors.initials: JC
authors.lastname: Byrd
authors.forename: Michael A
authors.initials: MA
authors.lastname: Freitas
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism; D002417:Cattle; D045744:Cell Line, Tumor; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D005561:Formates; D006657:Histones / Q000737:chemistry / Q000302:isolation & purification*; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood; D036103:Nanotechnology; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014269:Trifluoroacetic Acid
chemical_list: D005561:Formates; D006657:Histones; C030544:formic acid; D014269:Trifluoroacetic Acid