Jj. Harrahy et al., IDENTIFICATION OF A NEW PHOSPHORYLATION SITE IN CARDIAC-MUSCLE PHOSPHOFRUCTOKINASE, Biochemical and biophysical research communications, 234(3), 1997, pp. 582-587
The novel phosphorylation site (Ser(376)) that we discovered during in
vitro studies of the troponin C- or calmodulin-induced phosphorylatio
n of rabbit muscle phosphofructokinase [Zhao, Z., Malencik, D. A., and
Anderson, S. R. (1991) Biochemistry 30, 2204] also undergoes phosphor
ylation in the epinephrine-stimulated rabbit heart. Reversed-phase HPL
C and/or iron chelate affinity chromatography performed on CNBr digest
s of phosphofructokinase that had been isolated from epinephrine-treat
ed hearts yields a largely phosphorylated peptide corresponding to ami
no acid residues 371-378 of the enzyme. Mass spectrometry, gas phase s
equencing, and amino acid analyses establish the structure and phospho
rylation state of the peptide. (C) 1997 Academic Press.