Biochemistry Questions / Describe the mechanisms of action of defensins in the innate immune system. How do these peptides disrupt bacterial membranes and aid in controlling infections? Provide examples of infections where defensins are particularly effective.

Defensins are immune proteins secreted in response to a pathogen. Disrupting the formation of bacterial membranes, defensins prevent growth and thus help control a bacterial infection.

During the post-natal period, defensins are found in high concentrations in the colostrum while the baby’s immune system develops. This helps to prevent the risk of bacterial infection, supplementing the parts of the immune system present at that stage in life.

Defensins are an area of research in helping to combat antibiotic resistance. Some evidence suggests that defensins can help supplement antibiotic function, improving efficacy and potentially reducing the chance of resistance developing.