title: Copper(II) Ions Increase Plasminogen Activator Inhibitor Type 1 Dynamics in Key Structural Regions That Govern Stability.
abstract: Plasminogen activator inhibitor type 1 (PAI-1) regulates the fibrinolysis pathway by inhibiting the protease activity of plasminogen activators. PAI-1 works in concert with vitronectin (VN), an extracellular protein that aids in localization of active PAI-1 to tissues. The Peterson laboratory demonstrated that Cu(II) and other transition metals modulate the stability of PAI-1, exhibiting effects that are dependent on the presence or absence of the somatomedin B (SMB) domain of VN. The study presented here dissects the changes in molecular dynamics underlying the destabilizing effects of Cu(II) on PAI-1. We utilize backbone amide hydrogen/deuterium exchange monitored by mass spectrometry to assess PAI-1 dynamics in the presence and absence of Cu(II) ions with and without the SMB domain of VN. We show that Cu(II) produces an increase in dynamics in regions important for the function and overall stability of PAI-1, while the SMB domain elicits virtually the opposite effect. A mutant form of PAI-1 lacking two N-terminal histidine residues at positions 2 and 3 exhibits similar increases in dynamics upon Cu(II) binding compared to that of active wild-type PAI-1, indicating that the observed structural effects are not a result of coordination of Cu(II) to these histidine residues. Finally, addition of Cu(II) results in an acceleration of the local unfolding kinetics of PAI-1 presumed to be on pathway to the latency conversion. The effect of ligands on the dynamics of PAI-1 adds another intriguing dimension to the mechanisms for regulation of PAI-1 stability and function.
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee , Walters Life Sciences Building, 1414 Cumberland Avenue, Knoxville, Tennessee 37996, United States.|Department of Biological Sciences, Louisiana State University , A221 Life Sciences Annex, Baton Rouge, Louisiana 70803, United States.
authors.forename: Joel C
authors.initials: JC
authors.lastname: Bucci
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Southern Denmark , 55 Campusvej, 5000 Odense M, Denmark.
authors.forename: Morten Beck
authors.initials: MB
authors.lastname: Trelle
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee , Walters Life Sciences Building, 1414 Cumberland Avenue, Knoxville, Tennessee 37996, United States.
authors.forename: Carlee S
authors.initials: CS
authors.lastname: McClintock
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee , Walters Life Sciences Building, 1414 Cumberland Avenue, Knoxville, Tennessee 37996, United States.
authors.forename: Tihami
authors.initials: T
authors.lastname: Qureshi
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Southern Denmark , 55 Campusvej, 5000 Odense M, Denmark.
authors.forename: Thomas J D
authors.initials: TJ
authors.lastname: Jørgensen
authors.affiliation: Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee , Walters Life Sciences Building, 1414 Cumberland Avenue, Knoxville, Tennessee 37996, United States.|Department of Biological Sciences, Louisiana State University , A221 Life Sciences Annex, Baton Rouge, Louisiana 70803, United States.
authors.forename: Cynthia B
authors.initials: CB
authors.lastname: Peterson
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003300:Copper / Q000378:metabolism*; D041961:Deuterium Exchange Measurement / Q000379:methods; D005342:Fibrinolysis; D006639:Histidine / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D008024:Ligands; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D050505:Mutant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017395:Plasminogen Activator Inhibitor 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011487:Protein Conformation; D054730:Protein Interaction Domains and Motifs; D055550:Protein Stability; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013002:Somatomedins / Q000737:chemistry / Q000378:metabolism; D056811:Unfolded Protein Response; D019096:Vitronectin / Q000737:chemistry / Q000378:metabolism
chemical_list: D008024:Ligands; D050505:Mutant Proteins; D017395:Plasminogen Activator Inhibitor 1; D011994:Recombinant Proteins; C051321:SERPINE1 protein, human; D013002:Somatomedins; D019096:Vitronectin; D006639:Histidine; C016756:somatomedin B; D003300:Copper