November 1, 1986European Journal of Biochemistry
Substrate specificity of protein kinase C
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Discussion
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Implication
Biochemical analysis uncovers primary sequence requirements of protein kinase C across synthetic peptide substrates, indicating mechanisms governing selective cellular phosphorylation.
Key Points
- To determine the primary sequence determinants governing the selective substrate recognition of protein kinase C in physiological conditions.
- Synthesized peptides derived from known in vivo phosphorylation sites across four physiological substrates.
- Identified the in vitro phosphorylation site on the acetylated N-terminal serine of chick muscle lactate dehydrogenase.
- Evaluated enzyme kinetics (Km and Vmax) and compared cross-reactivity against cAMP-dependent protein kinase.
- Demonstrated a strong preference for a basic residue situated C-terminal to the target site, defined by the motif Ser/Thr-Xaa-Lys/Arg.
- Observed that flanking basic residues positioned both N- and C-terminal to the phosphorylation site substantially improve Km and Vmax values.
- Confirmed that physiological protein kinase C target peptides are poor substrates for cAMP-dependent protein kinase, establishing distinct site selectivity.
Cite This Study
Woodgett et al. (1986) studied this question.