| abstract |
1. A binding protein capable of binding at least one target comprising (a) a polypeptide chain, wherein said polypeptide chain contains VD1- (X1) n-VD2-C- (X2) n, where VD1 is the first heavy variable domain chains; VD2 represents the second variable domain of the heavy chain; C represents the constant domain of the heavy chain; X1 represents a linker, provided that it is not CH1; X2 represents the Fc region; and n is 0 or 1; (b) a polypeptide chain, wherein said polypeptide chain contains VD1- (X1) n-VD2-C- (X2) n, where VD1 is the first variable domain of the light chain; VD2 is the second variable domain of the light chain ; C is a constant domain of the light chain; X1 is a linker, provided that it is not CH1; X2 does not contain an Fc region; and n is 0 or 1; (c) comprising the first and second polypeptide chains, wherein said first polypeptide chain contains a first VD1- (X1) n-VD2-C- (X2) n, where VD1 is the first variable domain of the heavy chain; VD2 is is the second variable domain of the heavy chain; C is a constant domain of the heavy chain; X1 is a linker, provided that it is not CH1; and X2 represents an Fc region; where the specified second polypeptide chain contains a second VD1- (X1) n-VD2-C- (X2) n, where: VD1 is the first variable domain of the light chain; VD2 is the second variable domain of the light chain; C is a constant domain of the light chain ; X1 is a linker, provided that it is not CH1; and X2 does not contain an Fc region; and n is 0 or 1; or (d) four polypeptide chains, where two polypeptide chains contain VD1- (X1) n-VD2-C- (X2) n, where VD1 pr |