Coupling of poly(ethylene glycol) to albumin under very mild conditions by activation with tresyl chloride: characterization of the conjugate by partitioning in aqueous two-phase systems.
Poly(ethylene glycol) activated with tresyl chloride has been covalently linked to albumin as a result of a 2-h incubation in 0.05 M sodium phosphate buffer, pH 7.5, containing 0.125 M sodium chloride (0.344 OSM). The coupling of poly(ethylene glycol) to albumin was demonstrated by the increase in the partition coefficient of the protein in poly(ethylene glycol)-dextran aqueous two-phase systems. A linear relationship between the log of the partition coefficient of the poly(ethylene glycol)-albumin conjugate and the degree of modification (measured as the amino groups consumed during the coupling step) has been demonstrated. Countercurrent distribution in the two-phase system showed that poly(ethylene glycol)-albumin was heterogeneous with respect to its partitioning behavior, indicating that the albumin was not uniformly modified with poly(ethylene glycol).
Delgado
C
C
Department of Biochemistry and Chemistry, Royal Free Hospital School of Medicine, University of London, United Kingdom.
Patel
J N
JN
Francis
G E
GE
Fisher
D
D
D055598:Chemical Phenomena; D002621:Chemistry; D003377:Countercurrent Distribution; D006863:Hydrogen-Ion Concentration; D011092:Polyethylene Glycols; D012710:Serum Albumin, Bovine; D013450:Sulfones
D013450:Sulfones; C032605:2,2,2-trifluoroethanesulfonyl chloride; D012710:Serum Albumin, Bovine; D011092:Polyethylene Glycols