Antibiotic-resistant bacteria could be tackled with peptides derived from human proteins

Researchers from the Department of Medicine and Life Sciences at the Universitat Pompeu Fabra (MELIS-UPF) have collaborated in the identification of a new class of peptides with antimicrobial activity.

The study, led by the UAB and in which CIBER Infectious Diseases (CIBERINFEC), Vall d’Hebron University Hospital and IQS-CSIC also collaborated, has found regions of glycosaminoglycan-binding proteins (HBPs) that recognise and can combat antibiotic-resistant gram-negative bacteria.

Normally, these regions bind heparin to regulate clotting and inflammation. However, heparin is structurally similar to units on the surface of gram-negative bacteria, allowing HBPs to recognise and fight them as well. This has led the team to computationally analyse more than a hundred HBPs to identify these potential bacteria-binding regions and synthesise five peptides, or short protein sequences, based on these regions.

The generated peptides have shown potent in vitro activity against Escherichia coli, Pseudomonas aeruginosa or Acinetobacter baumannii, which can be resistant to antibiotics; the peptides have been less effective against gram-positive bacteria. In addition, the authors tested the effectiveness of one of the peptides in mice with very positive results, reducing the bacterial load in the organs.

According to Marc Torrent, UAB researcher and lead author of the article, these peptides have low toxicity in human cells, which “opens the door to a new family of antibiotics that can act specifically against resistant bacteria without affecting healthy cells”.