Beta lactamase

Beta-lactamase is an enzyme produced by some bacteria that provides resistance to beta-lactam antibiotics such as penicillins, cephamycins, and carbapenems (ertapenem), among others. Beta-lactamase provides multi-resistance to these antibiotics by breaking the antibiotics' structure. These antibiotics all have a common element in their molecular structure: a four-atom ring known as a beta-lactam. Through hydrolysis, the lactamase enzyme breaks the beta-lactam ring open, deactivating the molecule's antibacterial properties.

History

The first beta-lactamase was found in Escherichia coli in 1940 and was named penicillinase. Since then, many different types of beta-lactamases have been identified in various species of bacteria.

Classification

Beta-lactamases are usually classified into two major groups: the Ambler classification and the Bush-Jacoby-Medeiros classification. The Ambler classification is based on the protein homology, while the Bush-Jacoby-Medeiros classification is based on functional properties.

Mechanism of Action

Beta-lactamase enzymes are capable of breaking the beta-lactam ring of the antibiotic, rendering it ineffective. The beta-lactam ring is crucial for the antibiotic's ability to disrupt bacterial cell wall synthesis. Therefore, when the ring is broken, the antibiotic can no longer inhibit cell wall synthesis.

Clinical Significance

The production of beta-lactamase is a major cause of resistance to beta-lactam antibiotics. This resistance can lead to difficulties in treating bacterial infections, as many of the most commonly used antibiotics are beta-lactam based. Therefore, understanding the function and mechanisms of beta-lactamase is crucial in the development of new antibiotics.

See Also

• Antibiotic resistance
• Beta-lactam antibiotic
• Penicillin-binding protein
• Extended spectrum beta-lactamase