X-Ray Study Captures the Fast Chemistry Behind Penicillin Formation
Using time-resolved X-ray crystallography, researchers reconstructed a molecular movie of the rapid steps by which the enzyme IPNS builds penicillin's β-lactam ring. The study, published in Nature Catalysis, captured short-lived intermediates that had previously been impossible to observe directly. The findings may inform efforts to develop new antibiotics as antimicrobial resistance rises.
Penicillin's usefulness stems from a strained ring structure that disrupts bacterial cell wall construction, causing the microbes to burst and die. Oxford researchers turned it into a medicine in the early 1940s, and β-lactams have remained central to infection treatment since.
To watch IPNS work, the team combined ultrafast X-ray free-electron laser pulses with time-resolved crystallography, assembling snapshots taken at different moments into a continuous animation. This revealed a thioaldehyde species and a monocyclic β-lactam intermediate — the first ring formed — resolving a question open for over forty years.
Understanding how nature assembles the β-lactam ring could inform efforts to design new antibiotics, which may matter as resistance erodes current treatments. Patients facing resistant infections, drug developers, and public health systems could all be affected if such insights help refill a thin antibiotic pipeline. The work itself is basic science, so any clinical benefit would likely take years to materialize.