Defensins are Short Cationic Peptides That

Question

Defensins are short cationic peptides that
A) are produced by skin, GI-tract, and lung cells for defense when stimulated.
B) bind to specific protein receptors to gain entry into microbial cells.
C) are only produced by phagocytes upon activation.
D) inhibit microbial DNA synthesis.
E) are equally effective at killing eukaryotic and prokaryotic cells.

Accepted Answer

Defensins are peptides produced by various cells of the body, including skin, GI-tract, and lung cells, for defense against invading microorganisms. They have a positive charge due to the presence of arginine and lysine residues, which allow them to bind to the negatively charged microbial membranes and disrupt their structure. Defensins also have a broad range of activity against Gram-positive and Gram-negative bacteria, fungi, viruses, and even some cancer cells. However, they do not target specific protein receptors, nor do they inhibit DNA synthesis.