Turtle shield

Keeping from harm eggs of a marine turtle (Caretta caretta) contain a protein with antibacterial and antiviral properties, claims a research team from Kolkata.

The protein, found in egg white and called turtle egg-white protein, showed strong activity against Escherichia coli and Salmonella typhimurium, say researchers from the Indian Institute of Chemical Biology, Bose Institute, and the University of Calcutta. E coli causes urinary tract and intestinal diseases in humans and S typhimurium causes food poisoning and fever.The protein also showed significant antiviral activity against Chandipura virus, which causes encephalitis, especially in children.

"This protein has the potential to be developed as an antibacterial agent," says Siddhartha Roy, the lead researcher.

The protein was also tested on cultured baby hamster kidney cells infected with the Chandipura virus. "Its strong activity against Chandipura virus suggests that it may be developed as a first line of defence against this pathogen," he adds.

The scientists found that the protein was similar to defensins, a type of protein found in mammals and birds. "This is the first report of defensins in reptiles and eggs, indicating a widespread role of the innate immune system in protecting animals and eggs," says the study published in Proteins: Structure, Function, and Bioinformatics (Vol 64, No 2, August 1, 2006).