Wpływ reszt ΔPhe na konformację łańcucha peptydowego

In the past few years dehydropeptides have been highly investigated, mainly due to their biological activity: for instance, as antimicrobials or catalytic agents in some enzymes [1, 51-53]. In presented studies it was established that dehydrophenylalanine residue (ΔPhe) can be an interesting building block of various peptide chains, in order to control and modify a structure, conformation and function of the target molecule [3, 4, 5-7]. It was also pointed out that the length of a linker between dehydroamino acid residues (if two or more are present in a peptide chain) is a crucial factor in case of conformational dependence [23]. Short, one-residue spacers promote 3₁₀-helical structure, while longer ones increase the coexistence of 3₁₀-helical and α-helical conformers (Table 7). What is worth to notice, temperature or polarity of solvent can dramatically change the screw sense of obtained 3₁₀-helices (Table 11). Additionally, the screw sense can be altered by other variables, like chirality of C and N-terminus or dehydroamino acid isomer type (E or Z) [4-11]. Considering chain conformation, it can be disparate, depending on environment’s solid or liquid state (Table 7). Application of dehydropeptides is widely spread among assorted field of studies. As they can form a few self-assembled structures (e.g. nanotubes, nanovesicles or hydrogels), arise an opportunity of encapsulation of small drug molecules or trapping and releasing bioactive substances [47-49]. Sequences with incorporated dehydroamino acid residues were examined as a potential drug - interaction with negatively charged membrane of bacteria species is possible by virtue of positive polarization of peptide chain [51]. Part of the sequences exert an activity against E. coli, S. aureus, P. falciparum or highly dangerous MRSA, presenting versatile potential correlated with their secondary structure [50-53].