The Isolation and Characterization of Plasminogen Activators (Urokinase) from Human Urine^*

Abstract

mentation-equilibrium methods. It was homogeneous by all criteria applied. Type S2 urokinase showed a specific activity of 93,500 CTA units/mg and a molecular weight of 54,700 by the sedimentation-equilibrium method.

Effect of urokinase antiserum on plasminogen activators: demonstration of immunologic dissimilarity between plasma plasminogen activator and urokinase

“…Subsequently White, Barlow, and Mozen (6), who, by alternative methods prepared urokinase of comparable specific activity to that of Lesuk et al, described preparation inhomogeneity and the presence of at least three molecular species (S1, mol wt 31,500 and S2, mol wt 54,700, the main types). Type S, urokinase had a specific activity approximately twice that of S2, but antisera prepared against S, showed reaction of identity with S, material.…”

“…Thus the term tissue activator designates activators extracted from specific tissues; plasma and milk activators are those activators present in plasma and milk, respectively, and urokinase, the activator present in urine. Except in the case of human urokinase which has been highly purified (5,6) and porcine heart activator which has been substantially purified (15), little is known of the properties, precise origins, and interrelationships of the individual activators. Of particular significance are the interrelationships and identities of tissue activators, plasma activator, and urokinase.…”

“…Subsequent studies by Sobel, Mohler, Jones, Dowdy, and Guest (2), Williams (3), and Astrup and Sterndorff (4) demonstrated that this property was due to the presence of a plasminogen activator, named urokinase by the former group of investigators (2). Urokinase has been prepared in highly purified form (5,6), and one group (5) has reported its crystallization. While it is inferred that plasminogen activators appearing in body fluids originate from tissue sources, the original site of urokinase derivation is uncertain.…”

Proteolytic mechanisms involved in the metastasis of human melanoma cells

“…The structure of urokinase plasminogen activator Urokinase-type PA was first isolated from urine (39,40), from which its name is derived. uPA is secreted as a single chain zymogen of 54 kD (41)(42)(43).…”

Purification of High Molecular Weight Urokinase by Reverse-immunoadsorption

“…The former immunoadsorbent that bound only urokinase was needed for the preparation of contaminating proteins free of urokinase from the crude urokinase sample. Thus, the homogeneous HMW-UK purified by a published procedure 8 ) was used as an antigen to raise the anti-HMW-UK antisera in rabbits. The antisera obtained gave a single precipitin line against both the homogeneous HMW-UK and crude enzyme in the Ouchterlony double immunodiffusion test (data not shown), indicating the absence of other forms of urokinase (e.g.…”