The 2.0-A deg resolution crystal structure of a trimeric antibody fragment with noncognate V_H-V_L domain pairs shows a rearrangement of V_H CDR3

摘要

The 2.0-A deg resolution x-ray crystal structure of a novel trimeric antibody fragment, a "triabody," has been determined. The trimer is made up of polypeptides con- structed in a manner identical to that previously described for some "diabodies": a V_L domain directly fused to the C terminus of a V_H domain - i.e., without any linker sequence. The trimer has three Fv heads with the polypeptides arranged in a cyclic, head-to-tail fashion. For the particular structure reported here, the polypeptide was constructed with a V_H domain from one antibody fused to the V_L domain from an unrelated antibody giving rise to "combinatorial" Fvs upon formation of the trimer.