Patent ID: 7084113

Claim:
A method for producing a protein having an antithrombotic activity, which comprises replacing, in a protein that has the amino acid sequence of SEQ ID NO: 1 and forms a tertiary structure, from N-terminus to C-terminus, composed of a first β strand (β1), a first α helix (α1), a second α helix (α2), a second β strand (β2), a loop, a third β strand (β3), a fourth β strand (β4) and a fifth β strand (β5) in this order from the amino terminus, at least one amino acid residue in a region from α2 to β2 in the protein corresponding to the sequence of the amino acid residues 47 to 72 in SEQ ID NO: 1, a region from β3 to β4 in the protein corresponding to the sequence of the amino acid residues 94 to 111 in SEQ ID NO:1, or in the region from α2 to β2 and the region from β3 to β4 so that electric charge of the amino acid residue is substituted towards positive direction as compared to the unsubstituted amino acid.