Binding of sisomicin and streptomycin to human albumin

Abstract

The aminoglycosides of the kanamycin and neomycin series are displaced from their protein binding by very low Ca++ ion concentrations, whereas streptomycin is displaced only by very high Ca++ ion concentrations. For streptomycin, therefore, the binding mechanism must differ from that for the other aminoglycosides. The displacing reaction cannot be described by the law of mass action, combining the binding equations. Several possible reasons, such as complex formation and changes in the conformation of albumin, are discussed. Complex formation between sisomicin and the lanthanide ion Nd+++, which has the same ionic radius as the Ca++ ion, could be excluded by recording the difference absorption spectrum. The displacement of the aminoglycosides from their protein binding by Ca++ ions (as well as the pH dependence of the protein binding) suggests that ionic bonds are involved in the interactions between aminoglycosides and serum proteins.

Scatchard Plots with a Positive Slope and Role of Albumin Concentration

“…The sequential changes of buffer used in the dynamic dialysis technique may remove inhibitors of binding but seem unlikely to account for the results with the narcotic analgesics (1). Scholtan (20) found that drug binding in whole serum with pathologically lowered albumin concentration did not decrease as much as anticipated. Therefore, an increase in nK with lower albumin concentrations cannot be fully explained by dilution of endogenous inhibitory substances since no such dilution would have occurred in whole serum.…”

Calf serum constituent fractions influence polyethylene wear and microbial growth in knee simulator testing

“…Antibiotics such as penicillin and streptomycin, which were the main constituents of AA, were frequently used in clinical applications and were suggested to bind onto the albumin protein. [56][57][58] Such binding of AA onto polypeptide constituents might have protected them from bacterial attack. It remains to be seen which constituents of the AA were actually effective in inhibiting bacterial growth in the long term, but such investigations went beyond the scope of the present study.…”

Binding of streptomycin with bovine serum albumin: Energetics and conformational aspects

“…Though the interactions of some antibiotics with the serum albumin are reported in literature [11,[17][18][19], quantitative studies on the interaction of streptomycin with serum albumin addressing the energetics and type of interactions is not available in literature. A combination of isothermal titration calorimetry and fluorescence spectroscopy has yielded valuable information on binding interactions in biologically important systems both quantitatively and qualitatively [20][21][22][23][24][25].…”