Letter: Specific isotope labeling for the identification of free N-terminal peptide of proteins separated by polyacrylamide gel electrophoresis.
We report here a method for the identification of free N-terminal peptide of in gel digested isolated proteins. It is based in the difference between the isotopic ion distribution of N-terminal peptide and internal peptides. After guanidination of lysine residues, the primary amino groups of the gel-entrapped protein are blocked with an equimolar mixture of normal and deuterated acetic anhydride. Upon MS analysis internal peptides display a normal isotopic ion distribution while the N-terminal peptide shows a complex isotopic ion distribution.
Sanchez
Aniel
A
Ramos
Yassel
Y
Solano
Yanni
Y
González
Luis Javier
LJ
Betancourt
Lazaro
L
Gil
Jeovanis
J
Padron
Gabriel
G
Besada
Vladimir
V
D000089:Acetic Anhydrides / Q000737:chemistry; D003903:Deuterium; D004591:Electrophoresis, Polyacrylamide Gel; D007553:Isotope Labeling / Q000379:methods*; D010455:Peptides / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000089:Acetic Anhydrides; D010455:Peptides; C031800:acetic anhydride; D003903:Deuterium