Abstract
Four kinds of acidic subunits and three kinds of basic subunits of 11 S globulin were separated by polyacryl amide gel electrophoresis in the urea system. The four acidic subunits designated as A1, A2, A3 and A4 (Rm=0.35, 0.40, 0.46 and 0.56 respectively) were isolated by stepwise elution followed by repeating gradient elution with DEAE-Sephadex A-50 in the presence of 6M urea at 5°C.
Subsequently, some physico-chemical properties of the subunits were determined. For example, N-terminal amino acids were determined as phenylalanine for both A1 and A2 and as leucine (or isoleucine) for both A3 and A4 by the DNP-amino acid method. The molecular weights of A1, A2 and A3 were shown as 37, 000 and 45, 000 for A4 by SDS-gel electrophoresis. The amino acid compositions of the acidic subunits were roughly similar to each other, but some remarkable differences were observed in the content of basic amino acids (lysine, histidine and arginine), serine and proline.
