Inhibition of proteinase-like peptidase activities in serum and tissue from breast cancer patients.

Abstract

The inhibitory profiles of several proteinase-like peptidases active on synthetic peptide (MCA) substrates, present in sera and 100,000g supernatants of malignant tissue from patients with breast cancer, have been studied using a series of known inhibitors including epoxysuccinyl peptides (E-64, Ep-475), Z-Phe-Phe-diazomethane, PMSF, iodoacetamide, 1-10-O-phenanthroline, leupeptin, aprotinin, elastatinal and alpha 2-macroglobulin. While in general the inhibition profiles confirmed reported substrate specificities some anomalies were observed. In particular, the serum activities on two cathepsin B substrates were unaffected by specific cysteine proteinase inhibitors and in breast tissue only 20-37% of activity towards these two substrates was apparently due to the presence of endopeptidases. However, the potent inhibition of other proteinase-like activities by the epoxysuccinyl peptides and leupeptin, or similar inhibitors, may be useful agents in the study of methods of combating tumour spread.

• Authors: A Vasishta, P R Baker, P E Preece, R A Wood, A Cuschieri
• Journal: Anticancer research (Anticancer Res) 1988 Jul-Aug Vol. 8 Issue 4 Pg. 785-9 ISSN: 0250-7005 [Print] Greece
• PMID: 3052253 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Peptide Hydrolases

Topics

• Breast Neoplasms (blood, enzymology)
• Female
• Humans
• Kinetics
• Peptide Hydrolases (blood, metabolism, pharmacology)
• Protein Binding
• Substrate Specificity