Journal of Microbiology

Binding Sites for Lead Ion in Staphylococcus epidermidis: Kim, Mal Nam , Sung, Hye Yoon; J. Microbiol. 1995;33(3):228-233.

Abstract: As S. epidermidis cell was fractionated into cell wall, cell membrane, and cytoplasm, the cell membrane proved to be the most efficient absorbent for lead ion. Ultrasonication was effective, when the cells were treated during their exponential growth. The amount of the lead ion adsorbed in cell membrane decreased as hydrogen ion concentration of solution increased. Protein purified from the cell membrane showed higher adsorption capacity for the lead ion than peptidoglycan, teichoic acid from cell wall, or cell membrane lipid. Modification of carboxyl groups in the membrane protein with ethylenediamine and 1-ethyl-3-carbodiimide hydrochloride resulted in a considerable decrease of lead ion adsorption capability, suggesting that the main binding site for lead ion was the carboxyl groups of protein in cell membrane.

Adsorption of Pb^2+ in the components of bacterial cell membrane: Kim , Mal Nam; J. Microbiol. 1995;33(4):278-282.

Abstract: S. epidermidis cell was fractionated into cell wall, cell membrane and cytoplasm. The cell membrane adsorbed the most abundant Pb^2+ per unit dry weight of the three fractions tested. Adsorption behavior of Pb^2+ in lipid and protein, which are the main components of the cell membrane, indicated that phosphatidylethanolamine and phosphatidylinositol having phosphoryl group and gangliosides containing carboxyl groups adsorbed much more Pb^2+ than triglycerides lacking any chargeable functional groups. Protein purified from cell membrane adsorbed larger amount of Pb^2+ than total native cell membrane or cell membrane lipid.

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