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 (Pro51–Pro54), which constitutes 7%. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.