Human metallo-β-lactamase enzymes degrade penicillin

Nonribosomal peptides are assemblages, including antibiotics, of canonical amino acids and other molecules. beta-lactam antibiotics act on bacterial cell walls and can be cleaved by beta-lactamases. beta-lactamase activity in humans has been neglected, even though eighteen enzymes have already been annotated such in human genome. Their hydrolysis activities on antibiotics have not been previously investigated. Here, we report that human cells were able to digest penicillin and this activity was inhibited by beta-lactamase inhibitor, i.e. sulbactam. Penicillin degradation in human cells was microbiologically demonstrated on Pneumococcus. We expressed a MBLAC2 human beta-lactamase, known as an exosome biogenesis enzyme. It cleaved penicillin and was inhibited by sulbactam. Finally, beta-lactamases are widely distributed, archaic, and have wide spectrum, including digesting anticancer and beta-lactams, that can be then used as nutriments. The evidence of the other MBLAC2 role as a bona fide beta-lactamase allows for reassessment of beta-lactams and beta-lactamases role in humans.