Synthesis and conformational analysis of salivary proline-rich peptide P-B.
The 57-amino acid human salivary polypeptide P-B has been synthesized by the solid-phase method using 9-fluorenylmethoxycarbonyl (Fmoc) strategy. The circular dichroism (CD) spectroscopy, Fourier-transform infrared spectroscopy (FTIR) and molecular modeling methods have been used for conformational studies of P-B. Examination of the CD spectra of P-B showed the content of the secondary structure to be independent of temperature over the range 0-60 °C at pH = 7 as well as over the pH range of 2-12 at 37 °C. P-B adopts predominantly unordered structure with locally appearing β-turns. The cumulative results obtained using the CD and FTIR spectroscopic techniques indicate the percentage of the polyproline type-II (PPII) helix being as low as about 10%. Similarly, the molecular dynamics (MD) simulations reveal only a short PPII helix in the C-terminal fragment of the peptide (Pro(51)-Pro(54)), which constitutes 7%.
Kamysz
Elżbieta
E
University of Gdańsk, Sobieskiego 18, Gdańsk, Poland. kamysz@chem.univ.gda.pl
Sikorska
Emilia
E
D002942:Circular Dichroism; D006801:Humans; D008958:Models, Molecular; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D055273:Salivary Proline-Rich Proteins / Q000138:chemical synthesis* / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
D055273:Salivary Proline-Rich Proteins