Bacterial cell walls could hold clues to better human health, say CCMB scientists

Bacteria are enclosed by protective cell walls, made from a unique substance called peptidoglycan. This material is absent in other life forms, including humans, which is why many antibiotics target it.

A team of scientists led by Manjula Reddy at CSIR-Centre for Cellular and Molecular Biology (CCMB), Hyderabad, has found that bacteria sometimes make mistakes while building this wall. Instead of using the correct amino acid L-alanine, they occasionally use a structurally similar one called glycine. This weakens the wall and makes bacteria more vulnerable to antibiotics.

These findings have been published in the PNAS journal.

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The bacterial cell wall is made of sugars and short chains of amino acids. Dr. Reddy’s team discovered that bacteria have a special enzyme called PgeF (Peptidoglycan Editing Factor) to maintain the composition of the cell using a combination of genetics and high-resolution mass-spectrometry, according to the study’s first author, Shambhavi Garde.

Interestingly, a similar enzyme exists in humans. Called LACC1, it has been linked to several autoinflammatory diseases — conditions where the immune system is hyperactived, said Dr.Reddy. Though LACC1’s role isn’t fully understood, this study suggests it might be involved in how the body responds to bacterial infections.

“By studying such vulnerabilities in cell wall synthesis, new ways of blocking bacterial growth can be designed,” the scientists said in a press release.