Modified annexin proteins and methods for preventing thrombosis
AssigneeSurroMed, Inc.
InventorAnthony Allison
Life of this patent
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Abstract
A modified annexin protein, preferably annexin V, is used to prevent thrombosis without increasing hemorrhage. Annexin binds to phosphatidylserine on the outer surface of cell membranes, thereby preventing binding of the prothrombinase complex necessary for thrombus formation. It does not, however, affect platelet aggregation necessary for hemostasis. The modified annexin molecule can be a homodimer of annexin, an annexin molecule coupled to one or more polyethylene glycol chains, or an annexin molecule coupled to another protein. By increasing the molecular weight of annexin, the modified annexin is made to remain in circulation for sufficient time to provide a sustained therapeutic effect.
Claims41
An isolated modified annexin protein comprising an annexin protein coupled to polyethylene glycol.
An isolated modified annexin protein comprising an annexin protein coupled to an additional protein.
An isolated nucleic acid molecule selected from the group consisting of:
- a) an isolated bacterial nucleic acid molecule comprising a nucleic acid sequence encoding a protein selected from the group consisting of:
- i) SEQ ID NO:6;
- and
- ii) a protein having at least 95% sequence identity to SEQ ID NO:6;
- and
- b) a nucleic acid molecule which is fully complementary to any said nucleic acid molecule recited in a).
A method of screening for a modified annexin protein that modulates thrombosis, said method comprising:
- a) contacting a thrombosis test system with at least one test modified annexin protein under conditions permissive for thrombosis;
- b) assessing the antithrombotic activity in the presence of said test modified annexin protein;
- and
- c) comparing the antithrombotic activity in the presence of said test modified annexin protein with the antithrombotic activity in the absence of said test modified annexin protein, wherein a change in the antithrombotic activity in the presence of said test modified annexin protein is indicative of a modified annexin protein that modulates thrombotic activity.
A method for identifying a modified annexin protein for annexin activity, said method comprising:
- a) contacting activated platelets with at least one test modified annexin protein under conditions permissive for binding;
- b) assessing the test modified annexin-binding activity of said platelets;
- c) assessing the protein S-binding activity in the presence of said test modified annexin protein;
- and
- d) comparing the test modified annexin-binding activity and protein S-binding activity in the presence of said test modified annexin protein with the unmodified annexin-binding activity and protein S-binding activity in the presence of unmodified annexin protein, whereby a modified annexin protein with annexin activity may be identified.
Dependencies are inferred from the claim text.