| 摘要 |
There is provided by the invention a novel composition comprising, in at least partially purified form, an endopeptidase endogenous to biological cells. The endopeptidase is characterized by having a molecular weight of about 110,000 daltons as measured by SDS PAGE; by being substantially insensitive to PMSF, TPCK, E-64, leupeptin, bacitracin, phosphoramidon and pepstatin; by being substantially inhibited by EDTA and 1,10-phenanthroline; and by being capable of cleaving peptide substrates comprising an alpha helical structural of at least about twelve to fourteen amino acids wherein said helix has a hydrophobic face and a hydrophilic face, said cleavage occuring amino terminal to a lysine or arginine residue on the hydrophilic face positioned within the context of at least four nonpolar amino acids substantially aligned along the hydrophobic face of the helix. |
