THE PHOSPHORYLATION SITE AND DESMETHIONYL N-TERMINUS OF DROSOPHILA PHOSRESTIN-I IN-VIVO DETERMINED BY MASS-SPECTROMETRIC ANALYSIS OF PROTEINS SEPARATED BY 2-DIMENSIONAL GEL-ELECTROPHORESIS
T. Kinumi et al., THE PHOSPHORYLATION SITE AND DESMETHIONYL N-TERMINUS OF DROSOPHILA PHOSRESTIN-I IN-VIVO DETERMINED BY MASS-SPECTROMETRIC ANALYSIS OF PROTEINS SEPARATED BY 2-DIMENSIONAL GEL-ELECTROPHORESIS, European mass spectrometry, 3(5), 1997, pp. 367-378
Post-translational modifications of proteins play crucial roles in mod
ulating many cellular processes, In order to understand the physiologi
cal roles of post-translational protein modifications it is imperative
to determine the nature of the change in chemical structure involved
in each protein modification, In our earlier work, we developed a meth
od for the study of protein modification through a streamlined combina
tion of two-dimensional gel electrophoresis, in-gel digestion, high pe
rformance liquid chromatography and electrospray ionization tandem qua
drupole mass spectrometry, Using this method we determined the in vivo
phosphorylation site of phosrestin I to be Ser(366). Since our earlie
r work described the method only briefly, we will present a full descr
iption of the method in this paper, In addition, by using this method,
we also show that the N-terminus of phosrestin I is desmethionylated
in vivo, These techniques are easily adapted to the study of other pro
teins and will serve as powerful tools for the study of post-translati
onal protein modifications in general.