INVESTIGATION OF FIBROIN COMPOSITION OF B OMBYX-MORI SILK PROTEINS BYSDS-PAGE

The fibroin proteins directly extracted from silk glands of Bombyx mor i were used for polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate(SDS-PAGE). The subunit structure of fibroin mol ecule was discussed, It has been elucidated that the native fibroin mo lecule consists of subunits a, b and c with molecular weights of 280 k D, 230 kD and 25 kD, respectively, Since the amount of them is much mo re than that of the b subunit, the a and b subunits are the major comp onent of fibroin, Of which the b subunit is composed of smaller e subu nit of M(w) about 130 kD and f subunit of M(w) about 125 kD, linked by disulfide bonds.