Final answer:
The drug vancomycin combats bacterial infections by binding to peptidoglycan subunits and blocking crucial cell wall synthesis processes, such as transglycosylation and transpeptidation, leading to the bactericidal effect against gram-positive bacteria.
Step-by-step explanation:
The drug vancomycin works by interfering with the synthesis of peptidoglycan, which is vital for bacterial cell wall integrity. Vancomycin, a glycopeptide antibiotic discovered in the 1950s, inhibits cell wall biosynthesis by binding to the peptide chain of peptidoglycan subunits, thus blocking the processes of transglycosylation and transpeptidation. While similar to β-lactams in its bactericidal effect against gram-positive bacteria, vancomycin's function is distinct; it does not mimic peptidoglycan subunits nor directly inactivate penicillin-binding proteins but rather blocks the incorporation of cell wall subunits into the bacterial cell wall.
Antibacterial drugs such as vancomycin are crucial because peptidoglycan is unique to bacteria, making it a target for antibiotics aiming to weaken the bacterial cell walls. This selective toxicity is what makes antibacterial agents so effective in treating bacterial infections without harming human cells, which lack peptidoglycan. The specificity of vancomycin and its ability to prevent gram-positive bacterial growth by inhibiting cell wall synthesis underscores the importance of understanding bacterial structure and function for developing antibiotic treatments.