Peptides Incorporating 3,4-Dihydroxyprolines: Synthesis and Structural Study

Abstract

Although the most common types of secondary structures in proteins are helices and sheets, other types of structures also form, such as turns and loops. Turns play an important role, both structurally and functionally. With regard to the structural aspect, they intervene in the folding of the peptide chain, favoring the formation of a specific tertiary, globular or fibrous structure. With regard to the functional aspect, the turns are mainly located in the region of the proteins most exposed to the environment and, therefore, influence various processes, such as molecular and cellular recognition as well as interactions between peptide structures and nonpeptide substrates or receptors. In addition, the turns serve as templates for the design of new drugs, antigens and pesticides. The serine−proline sequence, in terms of its ability to induce β-turns, is present in proteins that regulate gene expression and DNA binding. In addition, this sequence is recognized as a substrate by numerous kinases, representing a preferential site for protein phosphorylation. As an application of our work on the synthesis of dihydroxyprolines, we will discuss the ability of the dihydroxyproline−proline domain to induce the formation of β-turns similar to those induced by the serine−proline pair in synthetic peptides. To this end, it is proposed to incorporate the proline−dihydroxyproline dimer (in blue) into peptide II. This novel peptide supports the possibility of the formation of hydrogen bonds similar to those of peptide I, which incorporates the serine−proline sequence (in blue).

Keywords

• amino acids
• peptides
• prolines
• supramolecular chemistry