title: Enzymatic properties of the phosphorylated urokinase-type plasminogen activator isolated from a human carcinomatous cell line.
abstract: Enzymatic properties of phosphorylated urokinase plasminogen activator (P-uPA) (1) extracted from human carcinomatous cell line Detroit 562 cells were compared with those of non-phosphorylated uPA of urinary origin (nP-uPA). Using plasminogen as a substrate, the Km and Kcat of P-uPA were higher than that of nP-uPA while the Kcat/Km was lower. By zymography, a greater degree of plasminogen activation was observed. Concanavalin A reacted to both the enzymes. P-uPA had a low affinity for the inhibitors of plasminogen activator PAI-1 and PAI-2, and was inhibited only by the excess amounts of inhibitors. For PAI-1, and the KIs of P-uPA was greater and for PAI-2, KI was higher for P-uPA. These alterations by phosphorylation enable uPA to be more efficient in a focal proteolysis through plasminogen activation.
authors.affiliation: Department of Physiology, Shimane Medical University, Izumo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: H C
authors.initials: HC
authors.lastname: Kwaan
authors.forename: E
authors.initials: E
authors.lastname: Koh
authors.forename: M
authors.initials: M
authors.lastname: Tanabe
mesh_terms: D000595:Amino Acid Sequence; D002277:Carcinoma; D002460:Cell Line; D003208:Concanavalin A / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D009842:Oligopeptides; D010766:Phosphorylation; D015849:Plasminogen Inactivators / Q000494:pharmacology; D013379:Substrate Specificity; D014568:Urokinase-Type Plasminogen Activator / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D009842:Oligopeptides; D015849:Plasminogen Inactivators; D003208:Concanavalin A; D014568:Urokinase-Type Plasminogen Activator