Evidence for the functional similarity between tumour cell surface guanidinobenzoatase and tissue type plasminogen activator
Steven, F.S.; Griffin, M.M.; Cederholm-Williams, S.A.; Mangel, W.F.; Maier, H.
Anticancer Research 11(2): 641-647
1991
ISSN/ISBN: 0250-7005 PMID: 1905903 Document Number: 387897
Tumour cells possess a cell surface protease referred to as guanidinobenzoatase (GB). The active centre of GB binds the fluorescent probe 9-amino acridine (9-AA) and this binding enables cells possessing active GB to be located by fluorescent microscopy. GB binding of 9-AA was inhibited by prior treatment of sections of tumour tissue with a specific polyclonal antibody recognising the tumour associated protease tissue plasminogen activator (t-PA). GB binding of 9-AA was also inhibited by prior treatment of sections of tumour tissues with PAI-1, a protein inhibitor of plasminogen activatory. We conclude from studies and kinetic analyses that GB and t-PA are very similar both in structure and function.