title: Expression of full-length human pro-urokinase in mammary glands of transgenic mice.
abstract: Human pro-urokinase expressed in the mammary glands of transgenic animals is quickly activated and converted to urokinase by proteases that are present in the milk. Thus, it is nearly impossible to isolate full-sized pro-urokinase from the milk of transgenic animals. To solve this problem, we constructed transgenic mice that express human pro-urokinase and modified ecotin, which is a potent serine protease inhibitor from E. coli, in their mammary glands. The gene encoding ecotin was modified so as to enhance its specificity for the human urokinase-type plasminogen activator. Co-expression of modified ecotin and human pro-urokinase in the mammary glands allows for purification of full-length human pro-urokinase from these transgenic mice. The results described here suggest a general way of preventing the activation of zymogens that are expressed in the mammary glands of transgenic animals by co-expression of a zymogen along with a protease inhibitor.
authors.affiliation: Institute of Gene Biology Russian Academy of Sciences, 119334 Moscow, Russia.
authors.forename: Yaroslav
authors.initials: Y
authors.lastname: Gursky
authors.forename: Robert
authors.initials: R
authors.lastname: Bibilashvili
authors.forename: Mikchail
authors.initials: M
authors.lastname: Minashkin
authors.forename: Alex
authors.initials: A
authors.lastname: Krasnov
authors.forename: Alex
authors.initials: A
authors.lastname: Deikin
authors.forename: Tatyana
authors.initials: T
authors.lastname: Ermolkevich
authors.forename: Andrey
authors.initials: A
authors.lastname: Popov
authors.forename: Lilia
authors.initials: L
authors.lastname: Verbovaya
authors.forename: Nicolai
authors.initials: N
authors.lastname: Rutkevich
authors.forename: Alexsander
authors.initials: A
authors.lastname: Shevelev
authors.forename: Sofia
authors.initials: S
authors.lastname: Georgieva
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Razin
authors.forename: Igor
authors.initials: I
authors.lastname: Goldman
authors.forename: Elena
authors.initials: E
authors.lastname: Sadchikova
mesh_terms: D000818:Animals; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D006801:Humans; D008321:Mammary Glands, Animal / Q000201:enzymology*; D051379:Mice; D008822:Mice, Transgenic; D033903:Periplasmic Proteins / Q000096:biosynthesis / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D014568:Urokinase-Type Plasminogen Activator / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification
chemical_list: C039076:Eco protein, E coli; D004792:Enzyme Precursors; D029968:Escherichia coli Proteins; D033903:Periplasmic Proteins; D011994:Recombinant Proteins; D014568:Urokinase-Type Plasminogen Activator; C067551:saruplase