The conformation of tetraalanine in water determined by polarized Raman, FT-IR, and VCD spectroscopy

The secondary structure of tetraalanine in water is determined by combining polarized Raman, FTIR, vibrational circular dichroism(VCD) and electronic circular dichroism(ECD). Tetraalanine exhibits a higher propensity for PPII than trialanine for which a 50:50 mixture of polyproline II and an extend beta-strand-like conformation was obtained from recent spectrosopic studies.