The nature of the infectious agents: PrP models of resistant species to prion diseases (dog, rabbit and horses)

TL;DR

This study analyzes the molecular structural dynamics of prion proteins in resistant species like dogs, rabbits, and horses to understand their immunity to prion diseases, revealing stability differences under various pH conditions.

Contribution

It provides the first detailed molecular structural dynamics analysis of prion proteins in resistant species, highlighting stability differences under different pH environments.

Findings

Dog and horse prion proteins are stable under neutral and low pH.

Rabbit prion protein is stable under neutral pH but unstable under low pH.

Low pH causes salt bridge disruption and structural collapse in rabbit prion protein.

Abstract

Prion diseases are invariably fatal and highly infectious neurodegenerative diseases affecting humans and animals. By now there have not been some effective therapeutic approaches to treat all these prion diseases. In 2008, canine mammals including dogs (canis familials) were the first time academically reported to be resistant to prion diseases (Vaccine 26: 2601--2614 (2008)). Rabbits are the mammalian species known to be resistant to infection from prion diseases from other species (Journal of Virology 77: 2003--2009 (2003)). Horses were reported to be resistant to prion diseases too (Proceedings of the National Academy of Sciences USA 107: 19808--19813 (2010)). By now all the NMR structures of dog, rabbit and horse prion proteins had been released into protein data bank respectively in 2005, 2007 and 2010 (Proceedings of the National Academy of Sciences USA 102: 640--645 (2005), Journal of Biomolecular NMR 38:181 (2007), Journal of Molecular Biology 400: 121--128 (2010)). Thus, at this moment it is very worth studying the NMR molecular structures of horse, dog and rabbit prion proteins to obtain insights into their immunity prion diseases. This article reports the findings of the molecular structural dynamics of wild-type horse, dog, and rabbit prion proteins. The dog and horse prion proteins have stable molecular structures whether under neutral or low pH environments. Rabbit prion protein has been found having stable molecular structures under neutral pH environment, but without structural stability under low pH environment. Under low pH environment, the salt bridges such as D177--R163 were broken and caused the collapse of the stable $\alpha$-helical molecular structures.