Penicillin Saved Millions of Lives. Now Scientists Have Uncovered Another Secret– www.techexplorist.com

Researchers were able to capture previously undocumented steps in the enzymatic process of producing penicillin. A thioaldehyde intermediate appeared prior to the formation of the ring; then, a single-ringed beta-lactam intermediate was observed, providing the first glimpse at the ring-shaped structure which will eventually form the complete penicillin scaffold.

The researchers found that water molecules within the enzyme guide the reaction towards completion. Changes in the enzyme’s structure and chemistry are coordinated to control the overall reaction, providing insight into how nature produces a drug molecule that is arguably one of the most recognizable in medicine.

The experiment was innovative in many ways. Thousands of microscopic crystals of the enzyme were mounted onto a continuous strip. When the strip passed into an area with high levels of oxygen, the chemical reaction started.

Scientists controlled the rate at which the strip moved through the oxygen chamber so they could determine how long each crystal had been reacting when it was hit by a single pulse of light from an XFEL. Each pulse of light created a snapshot of the structure of the enzyme at the atomic level.

Combine thousands of snapshots, and you get a molecular movie, a real-time view of penicillin biosynthesis.

Oxford has been central to penicillin’s story since the 1940s, when Howard Florey and Ernst Chain developed it into a usable drug during World War II. Dorothy Hodgkin later solved its structure using X-ray crystallography. This new study builds directly on that legacy, showing that even the most famous antibiotic still has secrets to reveal.