TY - JOUR
T1 - A new direction for anticoagulants
T2 - Inhibiting fibrin assembly with PEGylated fibrin knob mimics
AU - Stabenfeldt, Sarah E.
AU - Aboujamous, Nader M.
AU - Soon, Allyson S.C.
AU - Barker, Thomas H.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2011/10
Y1 - 2011/10
N2 - Current anticoagulants target coagulation factors upstream from fibrin assembly and polymerization (i.e., formation of fibrin clot). While effective, this approach requires constant patient monitoring since pharmacokinetics and pharmacodynamics vary from patient to patient. To address these limitations, we developed an alternative anticoagulant that effectively inhibits fibrin polymerization. Specifically, we investigated PEGylated fibrin knob "A" peptides, evaluating the effect of both polyethylene glycol (PEG) chain length (0, 2, 5, and 10-30kDa) and knob peptide sequence (GPRPAAC, GPRPFPAC, and GPRPPERC) on inhibiting fibrin polymerization (i.e., clot formation). Thrombin-initiated clotting assays with purified fibrinogen were performed to compare clot formation with each peptide-PEG conjugate. Results indicated a biphasic effect of PEG chain length, whereby, active-PEG conjugates demonstrated increasingly enhanced inhibition of fibrin polymerization from 0 to 5kDa PEG. However, the anticoagulant activity diminished to control levels for PEG chains above 5kDa. Ultimately, we observed a 10-fold enhancement of anticoagulant activity with active peptides PEGylated with 5kDa PEG compared to non-PEGylated knob peptides. The sequence of the active peptide significantly influenced the anticoagulant properties only at the highest 1:100 molar ratio where GPRPFPAC-5kDa PEG and GPRPPERC-5kDa PEG demonstrated significantly lower percent clottable protein than GPRPAAC-5kDa PEG. Moreover, human plasma treated with the active 5kDa PEG conjugate exhibited delayed prothrombin time to within the therapeutic range specified for oral anticoagulants. Collectively, this study demonstrated the utility of PEGylated fibrin knob peptides as potential anticoagulant therapeutics.
AB - Current anticoagulants target coagulation factors upstream from fibrin assembly and polymerization (i.e., formation of fibrin clot). While effective, this approach requires constant patient monitoring since pharmacokinetics and pharmacodynamics vary from patient to patient. To address these limitations, we developed an alternative anticoagulant that effectively inhibits fibrin polymerization. Specifically, we investigated PEGylated fibrin knob "A" peptides, evaluating the effect of both polyethylene glycol (PEG) chain length (0, 2, 5, and 10-30kDa) and knob peptide sequence (GPRPAAC, GPRPFPAC, and GPRPPERC) on inhibiting fibrin polymerization (i.e., clot formation). Thrombin-initiated clotting assays with purified fibrinogen were performed to compare clot formation with each peptide-PEG conjugate. Results indicated a biphasic effect of PEG chain length, whereby, active-PEG conjugates demonstrated increasingly enhanced inhibition of fibrin polymerization from 0 to 5kDa PEG. However, the anticoagulant activity diminished to control levels for PEG chains above 5kDa. Ultimately, we observed a 10-fold enhancement of anticoagulant activity with active peptides PEGylated with 5kDa PEG compared to non-PEGylated knob peptides. The sequence of the active peptide significantly influenced the anticoagulant properties only at the highest 1:100 molar ratio where GPRPFPAC-5kDa PEG and GPRPPERC-5kDa PEG demonstrated significantly lower percent clottable protein than GPRPAAC-5kDa PEG. Moreover, human plasma treated with the active 5kDa PEG conjugate exhibited delayed prothrombin time to within the therapeutic range specified for oral anticoagulants. Collectively, this study demonstrated the utility of PEGylated fibrin knob peptides as potential anticoagulant therapeutics.
KW - Coagulation
KW - Fibrinogen
KW - Polyethylene glycol
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U2 - 10.1002/bit.23184
DO - 10.1002/bit.23184
M3 - Article
C2 - 21520023
AN - SCOPUS:80051802611
VL - 108
SP - 2424
EP - 2433
JO - Biotechnology and Bioengineering
JF - Biotechnology and Bioengineering
SN - 0006-3592
IS - 10
ER -