| 摘要 |
A hybrid protein including protein fragments joined together by peptide bonds, the hybrid protein including, in sequential order, beginning at the amino terminal end of the hybrid protein, (a) the enzymatically active Fragment A of diphtheria toxin, (b) a fragment including the cleavage domain 11 adajacent Fragment A, (c) a fragment including at least the portion of Fragment B of diphtheria toxin encoded by the portion of the Fragment B encoding gene fragment of the tox operon between 11 and the position about 90 base pairs upstream from the position on the tox operon of the NRU I site of the tox<228> allele, and (d) a fragment including a portion of a cell-specific polypeptide ligand, such portion including at least a portion of the binding domain of the polypeptide ligand, such portion of the binding domain being effective to cause the hybrid protein to bind selectively to a predetermined class of cells to be attacked by enzymatically active Fragment A. |
