Weight, Ultracentrifugation and Electrophoretic Data

Molecular weight has been determined in several ways, the most commonly employed being determination by sedimentation equilibrium. In general, the molecular weight of human erythrocuprein is reported to be 33,600 (60) and the corresponding value for bovine erythrocuprein 32,600 (70). These values can be considered identical since they are within the experimental error. A summary of different determinations is given in Table 1. 

Electrophoretic studies of the isolated erythrocuprein employing starch or polyacrylamide gels have been carried out by most of the above-cited authors. The homogeneity was not as satisfactory as in the sedimentation experiments a major component and a slightly faster component were always detectable. At the moment it is not known whether there is a genuine second component or whether the erythrocuprein decomposes during the disc-electrophoretic separation. The electrophoretic separation pattern of bovine erythrocuprein is essentially the same for erythrocuprein from human tissues (64, 68). 

Molecular weight from Sedimentation equilibrium 32 500 690a (0.157% protein) 32 500 a 32 600k 32 800 c 32 6001 

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