Patent ID: 8835609

Claim:
An isolated antigen binding site for binding to a P2X purinoceptor 7 (P2X 7 ) receptor, the antigen binding site being defined by general formula: FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4-linker-FR1a-CDR1a FR2a-CDR2a-FR3a-CDR3β-FR4a wherein: FR1, FR2, FR3, FR4, FR1a, FR2a, FR3a and FR4a are each framework regions; CDR1, CDR2, CDR3, CDR1a, CDR2a, CDR3a are each complementarity determining regions; wherein: CDR1 has the amino acid sequence of SEQ ID NO: 5; CDR2 has the amino acid sequence of SEQ ID NO: 6; CDR3 has the amino acid sequence of SEQ ID NO: 33; CDR1a has the amino acid sequence of SEQ ID NO: 23; CDR2a has the amino acid sequence of SEQ ID NO: 24; and CDR3a has the amino acid sequence of (SEQ ID NO: 14).