March 3, 2023
A new study conducted at La Trobe University in Australia has revealed how crocodiles resist fatal fungal infections using a unique pH sensing mechanism, despite living in filthy water, reports EurekaAlert.
Published in the March edition of Nature Communications, the research could be used to create targeted treatment for fungal infections in humans. Such infections are becoming increasingly frequent due to growing antibiotic resistance.
Lead author from La Trobe University, Scott Williams, focused on the crocodiles’s ‘defensins’—small proteins that detect and announce an infection to the immune system.
“We solved structures of crocodile defensins and they look surprisingly like the same proteins in humans, which means we could use them as a template to treat fungal infections in humans,” Williams said.
“Crocodiles have great antifungal defenses and hopefully we’ll be able to adapt their defense to our own needs.”
Williams said it’s the first time this function has been found in any plant or animal.
“We haven’t seen the pH sensing mechanism in any other animal or plant. The defensins are able to change their activity based on the pH environment, so we could engineer other defensins to turn off or on depending on the presence of infection,” Scott Williams said.
“Some therapeutic treatments act on healthy cells by accident whereas this mechanism could help to reduce these off-target affects and focus on what’s harmful.”
Senior author Professor Mark Hulett said that the study is also the first to document the structure of the defensin membrane attack in high resolution.
“Using the power of the Australian Synchrotron, together with co-author Professor Marc Kvansakul, we were able generate structural data to define how defensins attack and kill fungal pathogens,” Hulett said.
“Consequently, our findings provide a model for understanding the anti-microbial activity of other defensins including those in humans.”
For this study, Professor Hulett harvested the crocodile tissue with the help of John Lever and John McGrath from the Koorana Crocodile Farm in Yeppoon, Queensland, the first commercial crocodile farm in Australia.
The findings of the study could allow researchers in the future to engineer defensins with pH-dependent activity in biotechnology and therapeutic applications, like treating serious infections in humans.
Research contact: @EurekAlert