title: Inhibition of a protease associated with tumour cells and the probable mechanism of regulation of this interaction in vivo.
abstract: The regulation of activity of a protease on the surface of human colonic tumour cells implanted in nude mice has been studied. A synthetic fluorescent probe was used to locate cells possessing active guanidinobenzoatase in frozen sections of tumour bearing tissues. These studies demonstrated the presence of intracellular protein inhibitors of guanidinobenzoatase which could be extracted in isotonic saline and transferred to the outer surface of the tumour cells. This study showed that the inhibition of guanidinobenzoatase was pH dependent and that the tumour cell may regulate the activity of its surface guanidinobenzoatase by exporting lactic acid.
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Biological Sciences, University of Manchester, U.K.
authors.forename: F S
authors.initials: FS
authors.lastname: Steven
authors.forename: H
authors.initials: H
authors.lastname: Maier
authors.forename: J
authors.initials: J
authors.lastname: Arndt
mesh_terms: D000818:Animals; D002265:Carboxylic Ester Hydrolases / Q000032:analysis* / Q000037:antagonists & inhibitors; D002460:Cell Line; D003110:Colonic Neoplasms / Q000201:enzymology* / Q000473:pathology; D010450:Endopeptidases / Q000032:analysis / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000032:analysis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D051379:Mice; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011480:Protease Inhibitors / Q000032:analysis*; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured / Q000201:enzymology
chemical_list: D004791:Enzyme Inhibitors; D011480:Protease Inhibitors; D002265:Carboxylic Ester Hydrolases; C037288:guanidinobenzoate esterase; D010450:Endopeptidases