Conversion of cathepsin E to enzymatic unstable form in gastric cancer cells.

Abstract

A new acid proteinase in human gastric cancer, named medium moving proteinase (Med.P), was found also in a gastric cancer transplanted into nude mouse. However, Med.P disappeared when the samples prepared from gastric cancer tissues were left for over 4 weeks at -80 degrees C, whereas the activity of cathepsin E (CE) increased. When these samples were reduced by dithiothreitol (DTT), Med.P appeared again and the CE activity decreased. These phenomena, revealed by electrophoretic analyses, indicated that Med.P is a monomeric form of CE (mono-CE). At weakly alkaline pH and after heating, mono-CE appeared to be more unstable than CE. These results indicated that CE assume an enzymatically unstable monomeric form in cancer cells.

• Authors: T Aoki, T Takasaki, T Furukawa, J Morikawa, T Yano, H Watabe
• Journal: Biological & pharmaceutical bulletin (Biol Pharm Bull) Vol. 18 Issue 11 Pg. 1522-5 (Nov 1995) ISSN: 0918-6158 [Print] Japan
• PMID: 8593471 (Publication Type: Journal Article)

Chemical References

• Isoenzymes
• Sulfhydryl Reagents
• Cathepsins
• Endopeptidases
• Cathepsin E
• Dithiothreitol

Topics

• Animals
• Cathepsin E
• Cathepsins (metabolism)
• Dithiothreitol (pharmacology)
• Electrophoresis, Polyacrylamide Gel
• Endopeptidases (metabolism)
• Humans
• Isoenzymes (metabolism)
• Mice
• Mice, Nude
• Stomach Neoplasms (enzymology)
• Sulfhydryl Reagents (pharmacology)
• Tumor Cells, Cultured