An exosite-specific ssDNA aptamer inhibits the anticoagulant functions of activated protein C and enhances inhibition by protein C inhibitor.
Activated protein C (APC) is a serine protease with anticoagulant, anti-inflammatory, and cytoprotective properties. Using recombinant APC, we identified a class of single-stranded DNA aptamers (HS02) that selectively bind to APC with high affinity. Interaction of HS02 with APC modulates the protease activity in a way such that the anticoagulant functions of APC are inhibited and its reactivity toward the protein C inhibitor is augmented in a glysoaminoglycan-like fashion, whereas APC's antiapoptotic and cytoprotective functions remain unaffected. Based on these data, the binding site of HS02 was localized to the basic exosite of APC. These characteristics render the exosite-specific aptamers a promising tool for the development of APC assays and a potential therapeutic agent applicable for the selective control of APC's anticoagulant activity.
Müller
Jens
J
Institute for Experimental Haematology and Transfusion Medicine, University Hospital Bonn, D-53105 Bonn, Germany.
Isermann
Berend
B
Dücker
Christina
C
Salehi
Mohammad
M
Meyer
Moritz
M
Friedrich
Max
M
Madhusudhan
Thati
T
Oldenburg
Johannes
J
Mayer
Günter
G
Pötzsch
Bernd
B
D000925:Anticoagulants / Q000037:antagonists & inhibitors* / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects; D052157:Aptamers, Nucleotide / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000819:agonists* / Q000378:metabolism; D006801:Humans; D011485:Protein Binding; D011486:Protein C / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D052156:SELEX Aptamer Technique; D013917:Thrombin / Q000378:metabolism
D000925:Anticoagulants; D052157:Aptamers, Nucleotide; D004791:Enzyme Inhibitors; D011486:Protein C; D013917:Thrombin