The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.
Vibrational circular dichroism as a probe of solid‐state organisation of derivatives of cyclic β‐amino acids:
Cis
‐ and
trans
‐2‐aminocyclobutane‐1‐carboxylic acid