Aly Moussa
Anses Lyon Laboratory, France
Title: The biological activity of streptomycin and related molecules are associated with the presence of 2 functional guanidine groups
Biography
Biography: Aly Moussa
Abstract
The presence of at least 2 functional guanidine groups within a non-polymeric hydrophilic molecular system was suspected to be the chemical structure of streptomycin implicated in the interaction with proteins. To prove this hypothesis, several chemicals possessing two guanidine groups as streptomycin (dihydrostreptomycin, bis-3-aminoproylamine, guanidine hydrochloride, triethylene tetra mine and spermine tetra-hydrochloride) were tested for evaluating their interaction with the pathogenic prion protein (PrPsc). All molecules sharing common chemical function with streptomycin reproduced aggregation and precipitation of the prion protein. The interaction of streptomycin with proteins is optimum at alkaline PH and takes place through hydrogen bond transfer between the 2 guanidine groups on streptomycin and the amino-acids of one or several prion peptides ruling the possibility of a Schiff-base reaction. Streptomycin had proved valuable for earlier and higher immunological detection of prions in clinical samples due to protein aggregation as well as to a better attachment of antibodies to their epitopes through electric charge transfer on the protein surface. These changes of the surface electrostatic charges induced by streptomycin affect also the prion stability leading to a reduced infectivity.