How B-lactam drugs work

How beta-lactam drugs workHow beta-lactam drugs work

Beta-lactam drugs are a classic way of treating bacterial infections. Since bacteria have cell walls and people don't, drugs that target cell wall synthesis should have fewer side effects. Beta-lactam drugs include penicillin, which was discovered by 1928 by Alexander Fleming. He observed that colonies of Penicillium mold growing in his bacterial cultures created zones where bacteria couldn't grow. He then isolated the specific compound that was responsible for this effect, penicillin. The term "beta lactam" refers to the four membered ring structure that is found in this class of antibiotics. The enzyme that penicillin and other beta-lactam antibiotics target is transpeptidase, which is involved in cell wall synthesis. It creates peptide crosslinks in the cell wall. When transpeptidase is inhibited, the cells burst from osmotic pressure. The beta lactam antibiotic where the peptide substrates usually bind. In this groove is a that is important for the catalysis of the peptide bond formation. Instead of reacting with the normal peptide substrate, the serine residue has formed a with the carbonyl carbon of the beta lactam, as can be seen by its bond length (a C-O bond is 0.14 nm), and the increased distance between the carbonyl carbon and the (a normal C-N bond distance is 0.15 nm; this is almost double that distance). You may include any references to papers as in: the use of JSmol in Proteopedia or to the article describing Jmol to the rescue.

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