Patent ID: 8062906

Claim:
An isolated B lymphocyte stimulator binding polypeptide comprising an amino acid sequence at least 90% identical to X 1 -X 2 -X 3 -Cys-X 5 -X 6 -X 7 -X 8 -X 9 -X 10 -X 11 -X 12 -X 13 -X 14 -Cys-X 16 -X 17 -X 18 (SEQ ID NO:5), wherein X 1 is Arg, Asp, Gly, His, Leu, Phe, Pro, Ser, Trp, Tyr, or is absent; X 2 is Ala, Arg, Asn, Asp, Gly, Pro, Ser, or is absent; X 3 is Arg, Asn, Gln, Glu, Gly, Lys, Met, Pro, Trp or Val; X 5 is Arg, Asn, Gln, Glu, His, Leu, Phe, Pro, Trp, Tyr, or Val; X 6 is Arg, Asp, Gln, Gly, Ile, Lys, Phe, Thr, Trp or Tyr; X 7 is Ala, Arg, Asp, Glu, Gly, Leu, Ser, or Tyr; X 8 is Asp, Gln, Glu, Leu, Met, Phe, Pro, Ser, or Tyr; X 9 is Asp, Leu, Pro, Thr, or Val; X 10 is Arg, Gln, His, Ile, Leu, Lys, Met, Phe, Thr, Trp or Tyr; X 11 is Ala, Arg, Asn, Gln, Glu, His, Leu, Lys, Met, or Thr; X 12 is Ala, Asn, Gln, Gly, Leu, Lys, Phe, Pro, Thr, Trp, or Tyr; X 13 is Ala, Arg, Gln, His, Lys, Met, Phe, Pro, Thr, Trp, or Tyr; X 14 is Arg, Gln, Glu, Gly, His, Leu, Met, Phe, Pro, Ser, Thr, Tyr, or Val; X 16 is Arg, Asp, Gly, His, Lys, Met, Phe, Pro, Ser, or Trp; X 17 is Arg, Asn, Asp, Gly, His, Phe, Pro, Ser, Trp or Tyr; and X 18 is Ala, Arg, Asn, Asp, His, Leu, Phe, or Trp, and wherein the B lymphocyte stimulator binding polypeptide binds a B lymphocyte stimulator protein selected from the group consisting of: (a) a protein whose amino acid sequence consists of amino acid residues 1-285 of SEQ ID NO: 173; (b) a protein whose amino acid sequence consists of amino acid residues 134-285 of SEQ ID NO:173; and (c) a trimer of the protein of (b).