Phosphorylation alters backbone conformational preferences of serine and threonine peptides

Su Yeon Kim, Youngae Jung, Geum Sook Hwang, Hogyu Han, Minhaeng Cho

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


Despite the notion that a control of protein function by phosphorylation works mainly by inducing its conformational changes, the phosphorylation effects on even small peptide conformation have not been fully understood yet. To study its possible effects on serine and threonine peptide conformations, we recently carried out pH- and temperature-dependent circular dichroism (CD) as well as 1H NMR studies of the phosphorylated serine and threonine peptides and compared them with their unphosphorylated analogs. In the present article, by performing the self-consistent singular value decomposition analysis of the temperature-dependent CD spectra and by analyzing the 3J(H N,H α) coupling constants extracted from the NMR spectra, the populations of the polyproline II (PPII) and β-strand conformers of the phosphorylated Ser and Thr peptides are determined. As temperature is increased, the β-strand populations of both phosphorylated serine and threonine peptides increase. However, the dependences of PPII/β-strand population ratio on pH are different for these two cases. The phosphorylation of the serine peptide enhances the PPII propensity, whereas that of the threonine peptide has the opposite effect. This suggests that the serine and threonine phosphorylations can alter the backbone conformational propensity via direct but selective intramolecular hydrogen-bonding interactions with the peptide N-H groups. This clearly indicates that the phosphoryl group actively participates in modulating the peptide backbone conformations.

Original languageEnglish
Pages (from-to)3155-3165
Number of pages11
JournalProteins: Structure, Function and Bioinformatics
Issue number11
Publication statusPublished - 2011 Nov


  • Blocked amino-acid
  • Circular dichroism
  • Peptide conformation
  • Phosphorylation
  • Polyproline II

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Biology


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