Fig. 1.
(A) Relationship of Mycograb C28Y variant antibody fragment to a full IgG antibody structure. The Mycograb C28Y variant is composed of the variable ends of the heavy (VH) and light (VL) chain from one arm of an antibody that binds to HSP90. (B) Structures of the Mycograb original sequence and the Mycograb C28Y variant. The schematic of the Mycograb and the Mycograb C28Y variant shows that the cysteine (C) at position 28 of the heavy chain fragment that is not paired in the molecule was changed to a tyrosine (Y) to decrease cross-chain binding, which could lead to aggregation. The linker protein sequence connects the two antibody variable region fragments together. The histidine tag at the end of the molecule (six-His tag) was used for protein purification. The end of the molecule stop sequence in the gene used to produce the Mycograb C28Y variant was included to prevent potential readthrough protein synthesis.