Abstract
Group-3 late embryogenesis abundant (G3LEA) proteins are expressed in anhydrobiotic organisms experiencing desiccation stress and their major segments consist of repeated and conserved 11-mer amino acid units. However, little information has been obtained with regard to the properties of these repeating units. Here, we synthesized three model peptides, each of which consists of two repeating units, and investigated their structures in solution and dry states by FT-IR spectroscopy. Furthermore, we examined how the structures of these peptides are influenced by addition of trehalose because this sugar is also produced massively in the dried cells of anhydrobiotic organisms. Consequently, it was shown that the secondary structure of these peptides transform from random coils to a-helical coiled coils in the response to dry stress, even in the presence of trehalose. In conclusion, the 11-mer repeating units act as core segments which could drive the structuralization of G3LEAs in the dry state.
