This is in contrast to the three high affinity ligands, which bound with the expected stoichiometry of one drug molecule bound per one mAb Fab site. corrects changes in volume at different temperature 3. It is also not clear how the interactions between them differ in a complex matrix such as the serum present in the human body. corrects for the presence of impurities in the reagents 2. Background Despite progress in cocaine immunotherapy, the kinetic and thermodynamic properties of antibodies which bind to cocaine and its metabolites are not well understood. Surprisingly, approximately 3.7 molecules of norcocaine are bound per mAb Fab site, as determined by isothermal titration calorimetry. IODINE VALUE Iodine Number Methods for Determination of Iodine Value 1. The much lower affinity cocaine metabolites, norcocaine and ecgonine methyl ester, have much lower binding enthalpies than the high affinity ligands, and in contrast to the three high affinity ligands, have favorable (positive) entropic thermodynamic components of binding. The proposed method of CE-MS/MS detection of cocaine in drugs is simple. The increased affinity of the cocaethylene metabolite compared to cocaine and benzoylecgonine is mostly attributable to a substantially less negative entropic binding component for cocaethylene, resulting in a more favorable binding energy, and thus, a higher affinity.
All three ligands that display high affinity (nM) binding to the mAb (cocaine, cocaethylene, and benzoylecgonine) displayed similar enthalpically driven binding with substantial enthalpy-entropy compensation. The calculated equilibrium dissociation (binding) constants were consistent with previous findings using other methods. Comparing Analytical Methods: Cocaine Determination in Urine. We analyzed the thermodynamics of binding of cocaine and several cocaine metabolites to a humanized anti-cocaine mAb (h2E2), which is under development for the treatment of cocaine use disorders, using isothermal titration calorimetry.
0 kommentar(er)
