defensín

Defensins are a class of small, positively charged peptides that are a crucial part of the innate immune system in many organisms, including humans, plants, and insects. They act as antimicrobial agents, meaning they can kill or inhibit the growth of a wide range of pathogens. This includes bacteria, fungi, viruses, and even some parasites.

The primary mechanism by which defensins exert their antimicrobial effect involves disrupting the cell membranes of target microbes. Their positive charge allows them to bind to the negatively charged components of microbial cell membranes. Once bound, they can insert themselves into the membrane, forming pores or channels. This disruption leads to leakage of essential intracellular components, ultimately causing cell death.

Defensins can be found in various locations within an organism, such as on mucosal surfaces (like the respiratory and gastrointestinal tracts), in phagocytic cells, and in the skin. This strategic distribution allows them to act as a first line of defense against invading pathogens. Beyond their direct antimicrobial activity, defensins also play a role in modulating the immune response by attracting immune cells to sites of infection and promoting wound healing. Their discovery and continued study are important for understanding host defense mechanisms and for developing new therapeutic strategies against infectious diseases.