Fucose sugar responsible for ricin’s lethal effects in humans, international study says

Two genes called Fut9 and SLc35c1, which regulate the metabolism of a particular sugar in cells, are responsible for making ricin so lethal to humans, according to a recently conducted study by researchers from the Austrian Academy of Sciences’ Institute of Molecular Biotechnology (IMBA).

The sugar, an essential monosaccharide called fucose, is responsible for attaching itself to proteins along the cell wall, which helps cells communicate within their environment.

The researchers found that the genes cause ricin’s toxic effects due to their ability to change the form and function of fucose by giving ricin access to the cells’ transport systems, which enables it to destroy ribosome molecules within an organism.

“Inhibiting these genes, for instance by means of a synthesized molecule, obstructs the transport of ricin into the cells and stops it reaching those parts where it can unleash such significant damage,” Jasmin Taubenschmid, IMBA Ph.D. student and co-lead author of the study, said. “This is because the poison requires a typical sugar signature on the cell wall to which it can attach.”

Through a special academic relationship with the University of Münster and Heidelberg University, the universities’ hospital departments provided IMBA with cell samples from a patient with a rare condition that rendered him unable to metabolize fucose due to a rare genetic disorder.

According to the researchers, the insights gained from studying that genetic defect contributed significantly to the idea of developing a preventative therapy against ricin poisoning.

IMBA protein researcher Johannes Stadlmann noted that previous research looked at proteins and sugar separately but the interaction between them was particularly fascinating, the result of which generated an entirely new level of information.