Plasmid-linked protection of [14C]-glutamate transport and its oxidation against Cd2+ in Staphylococcus aureus
Tynecka, Z.; Malm, A.; Skwarek, T.; Szcześniak, Z.
Acta Microbiologica Polonica 38(2): 131-141
1989
ISSN/ISBN: 0137-1320 PMID: 2482659 Document Number: 340055
The effect of Cd2+ on [14C]-glutamate transport energized by endogenous respiration and on glutamate oxidation was studied in the Cd2+-resistant and -sensitive Staphylococcus aureus strains. The results indicate that these processes are protected against 10 microM Cd2+ in the Cd2+ resistant strain 17810R by the 2H+/Cd2+ antiporter encoded by the cadA determinant located on a penicillinase plasmid p II17810. Even at 100 microM Cd2+, glutamate oxidation was only partially inhibited in this organism and this inhibition appeared to be reversible. In the plasmidless variant strain 17810S, which lacks the 2H+/Cd2+ antiporter, both [14C]-glutamate transport and its oxidation was blocked by Cd2+ at 10 or 100 microM. In this strain, Cd2+-mediated inhibition of glutamate oxidation was irreversible. Energetics of glutamate transport in both strains was analyzed.