Bacterial Antibiotic-Degrading Enzyme Found Bound to a DNA Fragment

This 1982 study, published in Biochimica et Biophysica Acta by Duez and colleagues, is not about skin or healing at all — it is basic enzyme chemistry from a soil bacterium. The researchers purified a beta-lactamase, an enzyme that breaks down penicillin-type antibiotics, secreted by a bacterium called Actinomadura R39.

They found the enzyme is a single protein chain of about 15,200 molecular weight, with an unusual shape and a low isoelectric point (pH 5.0). Attached to it, making up about 9.3% of its weight, was a polydeoxyribonucleotide — a short stretch of DNA — forming a stable complex with the protein. When the researchers used an enzyme called DNAase I to strip away much of this DNA fragment, the beta-lactamase kept working just as well, showing the DNA was not needed for its catalytic activity.

The team also measured how efficiently the enzyme broke down various antibiotics, finding nitrocefin to be its best substrate, with other penicillins and cephalosporins handled with varying efficiency.

As an isolated chemistry paper on a bacterial enzyme, this work says nothing about DNA fragments in human tissue, skin or wound repair.