title: Variant cathepsin L activity from gastric cancer tissue.
abstract: Cathepsin L activity was partially purified by S-Sepharose FF chromatography, concanavalin-A Sepharose chromatography, phenyl-Superose column chromatography, Mono S column chromatography, and TSK G3000SWXL column chromatography from gastric cancer tissue. The optimal pH of cathepsin L from gastric cancer tissue was 7.4, and the activity was retained even at alkaline pH. Heat stability tests showed that cathepsin L from gastric cancer tissue was heat stable; that is, 65% activity was retained after incubation at 56 degrees C for 60 min. The molecular weight of cathepsin L from gastric cancer tissue was estimated as 115 kD by gel filtration or 110 kD by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme showed a different affinity for wheat germ agglutinin-Sepharose than cathepsin L from gastric normal mucosa. These results suggest that cathepsin L from gastric cancer tissue may play an important role in gastric cancer invasion through the destruction of the surrounding extracellular matrix by its proteolytic activity.
authors.affiliation: Department of Preventive Medicine, Kyoto Prefectural University of Medicine.
authors.forename: S M
authors.initials: SM
authors.lastname: Chung
mesh_terms: D056668:Cathepsin L; D002403:Cathepsins / Q000302:isolation & purification* / Q000502:physiology; D003546:Cysteine Endopeptidases; D010450:Endopeptidases; D005753:Gastric Mucosa / Q000201:enzymology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008970:Molecular Weight; D013274:Stomach Neoplasms / Q000201:enzymology*
chemical_list: D002403:Cathepsins; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; C534281:CTSL protein, human; D056668:Cathepsin L