Erythromycin binding to human serum.
Erythromycin binding to human serum was measured under conditions of binding equilibrium. The binding is sensitive to pH changes, decreasing at acid pH. Over a great range of serum dilution, the bound fraction is semilogarithmically related to serum concentration. Binding is shown to be completely reversible. With increasing erythromycin concentration a specific part of binding is saturable and specifically displaceable by erythromycin is specifically bound to a single class of noninteracting binding sites with an apparent dissociation constant Kd = 5.9 microM (38 degrees C). The kinetic and thermodynamic parameters at 25 degrees are: Kd = 8.4 microM, delta H degrees = +4.4 X 10(3) cal per mole, delta  G degrees = 6.9 X 10(3) cal per mole, delta S degrees = +38 e.u.
D001798:Blood Proteins / Q000378:metabolism*; D004917:Erythromycin / Q000097:blood*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011485:Protein Binding; D013696:Temperature
D001798:Blood Proteins; D004917:Erythromycin