Antibiotics
PBPs bind β-lactam antibiotics because they are similar in chemical structure to the modular pieces that form the peptidoglycan. When they bind to penicillin, the β-lactam amide bond is ruptured to form a covalent bond with the catalytic serine residue at the PBPs active site. This is an irreversible reaction and inactivates the enzyme.
There has been a great deal of research into PBPs because of their role in antibiotics and resistance. Bacterial cell wall synthesis and the role of PBPs in its synthesis is a very good target for drugs of selective toxicity because the metabolic pathways and enzymes are unique to bacteria. Resistance to antibiotics has come about through overproduction of PBPs and formation of PBPs that have low affinity for penicillins (among other mechanisms such as lactamase production). Research on PBPs has led to the discovery of new semi-synthetic β-lactams, wherein altering the side-chains on the original penicillin molecule has increased the affinity of PBPs for penicillin, and, thus, increased effectiveness in bacteria with developing resistance.
Presence of the protein Penicillin binding protein 2A (PBP2A) is responsible for the antibiotic resistance seen in methicillin-resistant Staphylococcus aureus (MRSA).
The β-lactam ring is a structure common to all β-lactam antibiotics.
Read more about this topic: Penicillin Binding Proteins
Famous quotes containing the word antibiotics:
“Even diseases have lost their prestige, there aren’t so many of them left.... Think it over ... no more syphilis, no more clap, no more typhoid ... antibiotics have taken half the tragedy out of medicine.”
—Louis-Ferdinand Céline (1894–1961)