A major protease from human breast cancer cells was previously detected by gelatin
zymography and proposed to play a role in breast cancer invasion and metastasis. To
structurally characterize the enzyme, we isolated a cDNA encoding the protease. Analysis of
the cDNA reveals three sequence motifs: a carboxyl-terminal region with similarity to the
trypsin-like serine proteases, four tandem cysteine-rich repeats homologous to the low
density lipoprotein receptor, and two copies of tandem repeats originally found in the …