1/10/07

Cell Wall - a medical target

Source: Wikipedia + same lecture as the "Cell Specializations" - lecture slides

Cell Wall - a medical target

The cell wall is an important and common target for combating disease. This is because cell walls are not found in eukaryotes (so human cells remain safe).

Some antibiotics work in this way. Some antibiotics specifically interfere with synthesis of peptidoglycan. Consequently, there is little if any effect on the cells of humans and other eukaryotes.

Peptidoglycan: a polymer consisting of sugars and amino acids that forms a homogeneous layer outside the plasma membrane of eubacteria. Peptidoglycan serves a structural role in the bacterial cell wall, giving the wall shape and structural strength, as well as counteracting the osmotic pressure of the cytoplasm. Peptidoglycan is also involved in binary fission during bacterial cell reproduction.

Antibacterial drugs such as penicillin interfere with the production of peptidoglycan by binding to bacterial enzymes, transpeptidases. Transpeptidases form the bonds between oligopeptide crosslinks in peptidoglycan. For a bacterial cell to reproduce through binary fission, more than a million peptidoglycan subunits (NAM-NAG+oligopeptide) must be attached to existing subunits. Mutations in transpeptidases that lead to reduced interactions with an antibiotic are a significant source of emerging antibiotic resistance.

1 comment:

Candice said...

Well written article.