NR AQJC
AU Epple,G.; Langfeld,K.; Baier,M.; Holzhutter,H.G.; Schleuning,W.D.; Kottgen,E.; Gessner,R.; Praus,M.
TI Both lysine-clusters of the NH2-terminal prion-protein fragment PrP23-110 are essential for t-PA mediated plasminogen activation
QU Thrombosis and Haemostasis 2004 Mar; 91(3): 465-72
PT journal article
AB We have recently shown that the NH(2)-terminal fragment (PrP23-110) of the human cellular prion protein (PrPc ) stimulates t-PA mediated plasminogen activation. PrP23-110 contains an N-terminal lysine cluster (LC1; K(23),K(24), K(27)) and a C-terminal one (LC2; K(101),K(104),K(106),K(110)). To study their biological function we have substituted all lysine residues of each cluster by alanine and generated the recombinant PrP proteins PrP23-110sLC1 and PrP23-110sLC2. The ability of the mutant proteins to stimulate plasminogen activation was assayed. We found that both lysine clusters are essential for t-PA mediated plasminogen activation. We further studied the binding of soluble PrP23-110 to immobilized t-PA or plasminogen using surface plasmon resonance. The recorded binding curves could not be modeled by classical 1:1 binding kinetics suggesting oligomerisation of PrP23-110. Further plasmon resonance studies show that indeed PrP23-110 binds to itself and that glycosaminoglycans modify this interaction. Binding of t-PA or plasminogen to PrP23-110 was no longer influenced by glycosaminoglycans when PrP23-110 was immobilized on the chip surface. Thus a possible role of heparin as a cofactor in the stimulation of plasminogen activation by t-PA could be the generation of a PrP23-110 form with both lysine clusters accessible for binding of t-PA and plasminogen.
MH Blotting, Western; Dose-Response Relationship, Drug; Electrophoresis, Polyacrylamide Gel; Glycosaminoglycans/chemistry; Heparin/chemistry; Human; Kinetics; Lysine/*chemistry; Mutation; Plasmin/metabolism; Plasminogen Activators/*metabolism; Prions/*chemistry/genetics; Protein Binding; Protein Structure, Tertiary; Recombinant Proteins/chemistry; Surface Plasmon Resonance; Time Factors; Tissue Plasminogen Activator/*chemistry
AD Institut für Laboratoriumsmedizin und Pathobiochemie, Charite Berlin, Medizinische Fakultät der Humboldt Universität zu Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany.
SP englisch
PO Deutschland