Electrophoretic properties of beta-lactam and serum protein conjugates

Beta-lactam antibiotics can easy bind to protein. Available information on the nature of the conjugates is rather poor. In this study, agarose electrophoresis was used to determine and comparison physicochemical properties of the complexes. Benzylpenicillin, ampicillin, cefoperazone, cefotaxime, ceftazidime, cefuroxime, ceftriaxone, imipenem and serum protein were used for free generation drug-protein conjugates. Agarose electrophoresis shows heterogeneous migration of the conjugates. Interestingly-binding of benzylpenicillin and ampicillin exerts an effect on electrophoretic migration of albumin and globulin, but others--only serum albumin. Binding of ampicillin shows down migration of all anionic fractions of plasma protein, benzylpenicillin--anionic and cationic. Otherwise--migration of albumin was accelerate by others. This finding can explain higher frequency of penicillins hypersensitivity than cephalosporins, carbapenems or monobaktams. The commercially available and cheap procedure allows to execute the screening of physicochemical properties, which exert an effect on electrophoretic mobility of protein i.e. electric charge and molecule length (Stockes's diameter). Therefore, the electrophoretic mobility modification probably reflects the transformation of molecular weight, charge and space structure serum proteins by binding of beta-lactam antibiotics.