title: A substrate-like form of plasminogen-activator-inhibitor type 1. Conversions between different forms by sodium dodecyl sulphate.
abstract: Recombinant plasminogen-activator-inhibitor type 1 (PAI-1) purified in an active form from Escherichia coli and eucaryotic cells was found to contain a mixture of three functionally distinct forms: an active form that forms complexes with plasminogen activators (PAs), an inactive (latent) form that remains intact after incubation with PAs, and a substrate-like form which is easily cleaved by PAs. Since active PAI-1 purified from bacteria (rpPAI-1) contains only trace amounts of the inactive latent and the substrate-like forms, this material was used to study the effect of sodium dodecyl sulphate (SDS) on the structure and function of active PAI-1. After treatment with 0.01% SDS, active rpPAI-1 was converted to an inactive form that did not form complexes with PAs, but exhibited characteristics similar to those of latent PAI-1. After treatment with 0.1% SDS, PAI-1 lost its inhibitory activity and was cleaved as a substrate in the reactive center. Circular dichroism spectral analysis reveals that SDS changed the conformation of PAI-1 dramatically, mainly by increasing its alpha-helical content.
authors.affiliation: Department of Applied Cell and Molecular Biology, University of Umeå, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Urano
authors.forename: L
authors.initials: L
authors.lastname: Strandberg
authors.forename: L B
authors.initials: LB
authors.lastname: Johansson
authors.forename: T
authors.initials: T
authors.lastname: Ny
mesh_terms: D000577:Amides / Q000737:chemistry; D000818:Animals; D016466:CHO Cells; D002942:Circular Dichroism; D006224:Cricetinae; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000737:chemistry; D017395:Plasminogen Activator Inhibitor 1 / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D010960:Plasminogen Activators / Q000378:metabolism; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D013379:Substrate Specificity; D014162:Transfection
chemical_list: D000577:Amides; D017395:Plasminogen Activator Inhibitor 1; D011994:Recombinant Proteins; D012967:Sodium Dodecyl Sulfate; D010960:Plasminogen Activators