Conformation of one- and two-chain high molecular weight urokinase analyzed by small-angle neutron scattering and vacuum ultraviolet circular dichroism

Journal Article · Sat May 25 00:00:00 EDT 1991 · Journal of Biological Chemistry; (USA)

OSTI ID:5639112

Mangel, W F; Lin, B H; Ramakrishnan, V ^[1]

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1. Brookhaven National Laboratory, Upton, NY (USA)

The structures of one- and two-chain high molecular weight human urokinase were analyzed by small-angle neutron scattering and vacuum ultraviolet circular dichroism. Both one- and two-chain high molecular weight urokinases exhibited a radius of gyration of 31 A and a maximum dimension of 90 A. Neither parameter was affected by the presence of lysine sufficient to saturate all the lysine-binding sites in human plasminogen. These physical parameters are consistent with the sedimentation coefficient of high molecular weight urokinase and indicate that both proteins are highly asymmetric. Neither protein contained much alpha-helix or parallel beta-sheet. Most of the secondary structure was in the form of antiparallel beta-sheet and beta-turns, very similar to the secondary structure of plasminogen. The macroscopic kinetic constants, Km and kcat, for the hydrolysis of (pyroGlu-Gly-Arg-NH)2-rhodamine by two-chain high molecular weight urokinase and low molecular weight urokinase which lacks the epidermal growth factor and kringle domains were similar. These structural and kinetic data are consistent with the domains in both forms of urokinase being independent structural and functional units.

• OSTI ID: 5639112
• Journal Information: Journal of Biological Chemistry; (USA), Vol. 266:15; ISSN 0021-9258
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
UROKINASE
MOLECULAR STRUCTURE
MAGNETIC CIRCULAR DICHROISM
MOLECULAR WEIGHT
NEUTRONS
SCATTERING
SPECTROPHOTOMETRY
BARYONS
BLOOD COAGULATION FACTORS
COAGULANTS
DICHROISM
DRUGS
ELEMENTARY PARTICLES
ENZYMES
FERMIONS
FIBRINOLYTIC AGENTS
HADRONS
HEMATOLOGIC AGENTS
HYDROLASES
NONSPECIFIC PEPTIDASES
NUCLEONS
ORGANIC COMPOUNDS
PEPTIDE HYDROLASES
PROTEINS
550201* - Biochemistry- Tracer Techniques