title: Peptide fractionation by acid pH SDS-free electrophoresis.
abstract: SDS-free polyacrylamide gel electrophoresis is an effective alternative approach to peptide fractionation. Here we describe a discontinuous buffer system at acid pH that improves the separation of acidic peptides from tryptic digestion. MOPS and chloride act as trailing and leading ions, respectively, in this system, while histidine operates as counterion and buffers all solutions. In these electrophoretic conditions, peptides with pI below 5.5 migrate with low overall electrophoretic mobilities but high differences from one another, which allows for their efficient resolution. In silico analysis of several proteomes shows that the acid pH system allows a peptide simplification of 2.5-fold with respect to the total peptide mixture, and still a proteome coverage of about 95% is achievable. A straightforward method with a protocol including proteomic studies was achieved for SDS-PAGE of proteins, enzyme treatment and further peptide fractionation by SDS-free acid PAGE.
authors.affiliation: Center for Genetic Engineering and Biotechnology, La Habana, Cuba.
authors.forename: Yassel
authors.initials: Y
authors.lastname: Ramos
authors.forename: Yairet
authors.initials: Y
authors.lastname: Garcia
authors.forename: Yasset
authors.initials: Y
authors.lastname: Pérez-Riverol
authors.forename: Alejandro
authors.initials: A
authors.lastname: Leyva
authors.forename: Gabriel
authors.initials: G
authors.lastname: Padrón
authors.forename: Aniel
authors.initials: A
authors.lastname: Sánchez
authors.forename: Lila
authors.initials: L
authors.lastname: Castellanos-Serra
authors.forename: Luis J
authors.initials: LJ
authors.lastname: González
authors.forename: Vladimir
authors.initials: V
authors.lastname: Besada
mesh_terms: D000818:Animals; D003198:Computer Simulation; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010446:Peptide Fragments / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D011506:Proteins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D014357:Trypsin / Q000378:metabolism
chemical_list: D010446:Peptide Fragments; D011506:Proteins; D014357:Trypsin