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

摘要

An aspartic enzyme having a high homology with a cathepsin D precursor, which is a protein having the N-terminal amino acid sequence LVRIPLHKFT and showing a molecular weight of about 45 kDa in non-reductive SDS electrophoresis and can degrade plasma proteins, typically plasminogen, to produce plasma protein fragments having an inhibitory activity to metastasis and growth of cancer; the plasma protein fragments having an inhibitory activity to metastasis and growth of cancer which is prepared via the degradation with the above enzyme; a process for preparing the protein fragments which comprises degrading plasma proteins with the above enzyme; and a medicament for treating and preventing metastasis and growth of cancer which comprises as a major ingredient the above enzyme or the plasma protein fragments.