ENZYME PRODUCING PLASMA PROTEIN FRAGMENT HAVING EFFECT OF INHIBITING CANCER METASTASIS AND PLASMA PROTEIN FRAGMENT FRAGMENTED BY THE ENZYME

摘要

An aspartic acid enzyme having a high homology with a cathepsin D precursor, which is a protein starting at the N-terminal amino acid residue with LVRIPLHKFT and showing a molecular weight of about 45 kDa in non-reductive SDS electrophoresis and can degrade plasma proteins typified by plasminogen molecular species to give a plasma protein fragment having an effect of inhibiting cancer metastasis; the plasma protein fragment having an effect of inhibiting cancer metastasis which is prepared via the degradation with the above enzyme; a process for preparing the protein fragment having an effect of inhibiting cancer metastasis which comprises degrading a plasma protein with the above enzyme; and remedies against cancer metastasis which contain as the major ingredient the above enzyme or a fragmented plasma protein.