Peptides

Why in News?

A study published in the Proceedings of the National Academy of Sciences (PNAS) reports that specific peptides remain stable in 98% concentrated sulphuric acid.

• Peptides – It is a short chain of amino acids linked together by chemical bonds called peptide bonds.
• Characteristics
  • Building blocks – Made up of amino acids, the basic units of peptides.
  • Size – Generally contain 2–50 amino acids; longer chains are usually classified as polypeptides/proteins.
  • Formation – The carboxyl group of one amino acid joins the amino group of another.
  • Chemical process – Formation releases a water molecule, called condensation/dehydration synthesis.
• Functions & Uses
• In the Human Body
  • Hormonal signalling – It regulates various biological processes.
  • Immune defence – It supports protection against pathogens.
  • Muscle repair – It involved in tissue maintenance and repair.
  • Digestion – Certain peptides participate in digestive processes.
  • For example, insulin is a peptide hormone that regulates blood glucose levels.
• Skincare & Wellness
  • In skincare, peptides are incorporated into creams and serums to promote skin firmness and facilitate repair.
  • Supplements – Some peptide-based products are marketed for muscle recovery and wellness, though their effects depend on the specific peptide and product.

• Previous Scientific Assumptions – Concentrated sulphuric acid is considered extremely harsh, as it destroys biological molecules and is therefore unlikely to support complex chemical processes.
• Recent Research Findings – In 98% concentrated H₂SO₄, certain peptides remain stable for several weeks.
• Peptide bonds are not readily hydrolyzed under these conditions.
• Peptides are able to fold into specific three-dimensional structures, may potentially facilitate biological functions.
• Key finding
• Peptides were observed to form an omega-loop structure in concentrated sulphuric acid.
• Sulphuric acid molecules functioned as a scaffold, stabilizing the peptide structure.
• This mechanism differs from protein folding in aqueous environments, where structures such as α-helices and β-sheets are typically observed.
• Peptide stability in concentrated sulphuric acid challenges prior assumptions, suggesting Venus’ acid clouds may support complex chemistry and potential life.

Reference

The Hindu | Peptides