It has an IC50 more than 1000 times as potent as any past inhibitors we have tested this finding will cause us to modify our research direction to some extent. A new compound, based on aminimide synthesis, was tested just as this report was being prepared. These groups can aid inhibitor uptake, binding specificity, and binding strength. A search has been initiated to screen for pendants which can be attached to the platform and which make strong and specific interactions at other sites. A previous platform, 9-oxoguanine, has been shown to be of limited synthetic utility, however, 9-deaguanine appears to be a more versatile specificity site platform and should allow a range of pendant additions. Inhibitors which bind to the RTA substrate specificity site have been identified. Computer modeling and X-ray screening aid in the design process. The goal of this project is use the X-ray structure of ricin A chain RTA as a template for inhibitor design. The Army is pursuing anti-ricin vaccines, but plans to develop an efficacious antidote to the toxin, for cases where vaccination is not appropriate. Abstract: Ricin is a cytotoxin and a known bioterrorist weapon.

Ricin antidote