Nascent helix in the multiphosphorylated peptide αSs-Casein(2-20)

Abstract

Sequence-specific nuclear magnetic resonance (NMR) assignments have been determined for the peptide αS2-CN(2-20) containing the multiphosphorylated Motif-8Ser(P)-Ser(P)-Ser(P -Glu-Glu12- in the presence of molar excess Ca2+. The secondary structure of the peptide was characterized by sequential (i,i + 1), medium-range (i,i + 2/3/4) nOes and Hα chemical shifts. Molecular modelling of the peptide based on these constraints suggests a nascent helix for residues Ser(P)9 to Glu12. The spectral data for αS2-CN(2-20) were compared with those of other casein phosphopeptides β-CN(1-25) and αS1-CN(59-79) that also contain the multiphosphorylated motif. This comparison revealed a similar pattern of sec..