Abstract
The molecular weight of γ3 globulin was determined to be 120, 000 daltons by means of both sedimentation equilibrium and gel filtration methods. The protein was composed of 3 identical major and 1 minor subunits, and the molecular weights of them were found to be 35, 000 and 13, 000 daltons, respectively, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The major subunit has an arginyl residue as the amino terminal amino acid. The amino acid and carbohydrate composition of γ3 globulin was determined as follows: Lys37His37Arg92Asp60Glu139Gly120Ala83Val76Leu70Ile31Pro54Ser77Thr33 Cys11Met9Phe51Tyr26Trp8 (Amide NH3)69Hexose15Pentose4Hexosamine4. The structure of γ3 globulin was discussed with comparing that of γ1 globulin.
