Symmetry model sheds light on the chemistry surrounding peptide helices

Helices are structures found naturally in many important molecules, such as proteins. These helices possess a twist that depends on the arrangement of their basic components. By understanding how a helix is formed, we can gain deeper insights into how these structures influence the behavior of proteins in our bodies.

In peptides, which are smaller fragments of proteins, their helical shape arises from the repetition of specific blocks known as amino acids. These units can be arranged to create a new chiral layer, adopting a special orientation that affects the properties of the peptide. Chirality, therefore, plays a crucial role in how these molecular structures are organized and function.

A study published in Nature Communications explores this new layer of chiral information that can be generated in alpha-helical conformations of peptides.

By examining the different types of helices that can form, the authors have described, for the first time, a symmetry model that enhances our understanding of their relationships. Led by Dr. Julián Bergueiro at the Center for Research in Biological Chemistry and Molecular Materials (CiQUS), the study details how different amino acid sequences influence the arrangement and properties of these helical structures.

To achieve this, the team employed computational techniques and circularly polarized light spectroscopy, a suitable method for analyzing how molecules interact with chiral light. This approach allowed them to characterize various exo-helical topologies that precisely matched theoretical predictions.

“The results indicated that different patterns or ways of repeating amino acids lead to distinct helical structures. This is essential for understanding how many proteins carry out their biological activities and offers potential for designing new molecules for applications in medicine, biotechnology, or new biocompatible materials,” explains Bergueiro.

Controlling the sequence of monomers would allow for the design of specific topologies along the polymer chain, presenting a new approach in macromolecular engineering. This study marks a significant advancement in the field of peptide chemistry, transforming our understanding of how helical structures can be potentially harnessed in the development of new compounds and technologies.