Summary
Monoclonal antibodies against urinary urokinase were obtained by immunizing mice with
purified human high molecular weight urokinase. Five antibodies were selected and
denominated MPW1UK, MPW2UK, MPW3UK, MPW4UK, and MPW5UK, respectively. All selected
antibodies reacted with high and low molecular weight urokinase. Cleavage of the low
molecular weight paranitroanilide substrate pyro-Glu-Gly-Arg-pNA by urokinase was
not inhibited by the antibodies and only one antibody (MPW5UK) inhibited plasminogen
activation by urokinase. The ability of MPW5UK to bind to coated urokinase was 100-fold
higher than that of the other antibodies. MPW5UK was used to prepare an immunosorbent
for the purification of urokinase antigen from freshly voided crude urine. One-chain
prourokinase was separated from two-chain urokinase by chromatography of the urokinase
antigen containing mixture on agmatine Sepharose. As judged by SDS gel electrophoresis
one-chain prourokinase as well as two-chain urokinase were purified to apparent homogeneity
by this two-step procedure; the yields were 18% and 47% for single-chain prourokinase
and two-chain urokinase, respectively, as calculated from total urokinase antigen
contained in the starting material.
Keywords
Monoclonal antibodies - Two-chain urokinase - Single-chain prourokinase - Affinity
purification