Doxycycline and penicillin target bacteria differently. Penicillin, a beta-lactam antibiotic, inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs). This prevents the cross-linking of peptidoglycans, weakening the cell wall and leading to bacterial lysis.
Doxycycline, a tetracycline, functions by binding to the 30S ribosomal subunit of bacteria. This prevents the attachment of aminoacyl-tRNA to the mRNA-ribosome complex, halting protein synthesis. The inability to create essential proteins leads to bacterial death.
Therefore, these antibiotics employ distinct mechanisms. Penicillin disrupts cell wall construction; doxycycline interferes with protein production. This difference explains their varying effectiveness against different bacterial species and offers opportunities for combination therapy.
