| abstract |
A polypeptide consisting of the amino acid sequences SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4 and SEQ ID NO: 5, in which SEQ ID NO: 2 and 4 are linked by a disulfide bond in amino acid positions 57 and 111 in reference to SEQ ID NO: 1, and SEQ ID NO: 3 and 5 are linked by (a) a disulfide bond at amino acid positions 82 and 142 in reference to SEQ ID NO: 1, and (b) a disulfide bond at amino acid positions 86 and 144 in reference to SEQ ID NO: 1. |