Incubation of ferrihemoglobin as well as of hemoglobin isolated chains in ferri‐form with hemopexin at pH 7.0 leads to the gradual transfer of heme to the hemopexin molecules until the equilibrium is attained. The reaction of ferrihemoglobin with hemopexin can be described as a four‐stage process involving successive transfer of the four heme groups from hemoglobin tetramer to the four molecules of hemopexin. The heme binding sites of the hemoglobin molecule are nonequivalent and cooperative. The transfer of heme from the isolated hemoglobin chains in ferri‐form occurs as the simple competitive reaction which can be characterized by a single equilibrium constant. The affinity constant value for the binding of heme to the single binding center of hemopexin molecule was estimated as 1.9 × 1014× M−1. The direct transfer of heme from hemoglobin to hemopexin may occur in vivo as a part of hemoglobin degradation process.

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SummaryGlucose oxidase was immobilized by covalent bond to two basic types of sorbentsglycidylmethacrylate copolymers and bead cellulose. These two types of carriers were chemically modified, if needed, by employing various procedures and subsequently used in the immobilization of native and oxidized glucose oxidase. The samples thus obtained were compared with those of immobilized glucose oxidase bound onto some common carriers. Samples which possessed not only a high absolute activity but also adequate mechanical and flow properties were characterized in greater detail with respect to the immobilization efficiency and kinetic properties of bound glucose oxidase.

SUMMARYGlucose oxidase was immobilized on modified glycidyl methacrylate carriers after periodate oxidation of its glycosidic component either by a direct reaction of the formed aldehyde groups with amino groups of the carrier or using a modified four-component Ugi's reaction. The conjugates formed by the latter reaction exhibited higher activity and efficiency of immobilization.