Iliades P, Kortt A A, Hudson P J
CSIRO, Division of Biomolecular Engineering, Parkville, Victoria, Australia.
FEBS Lett. 1997 Jun 16;409(3):437-41. doi: 10.1016/s0014-5793(97)00475-4.
A single chain Fv fragment (scFv) of the murine monoclonal antibody 11-1G10 was constructed by directly joining the C-terminal residue of the V(H) domain to the N-terminal residue of V(L). 11-1G10 is an anti-idiotype and competes with the antigen, influenza virus neuraminidase (NA), for binding to the NC41 antibody. The scFv formed stable trimers with three active antigen combining sites for NC41 Fab fragments. We propose that trimeric scFvs may be the preferred conformation for directly linked V(H)-V(L) molecules, which contrasts the formation of scFv dimers (diabodies) when the V(H) and V(L) domains are joined by short flexible linkers of between 5-10 residues. BIAcore biosensor binding experiments showed that the trimeric scFv showed an expected increase in binding affinity, due to avidity, compared to the monomeric 15-residue linked scFv. The increase in avidity of scFv trimers offers advantages for imaging and immunotherapy.
通过将V(H)结构域的C末端残基直接连接到V(L)的N末端残基，构建了鼠单克隆抗体11-1G10的单链Fv片段（scFv）。11-1G10是一种抗独特型抗体，可与抗原流感病毒神经氨酸酶（NA）竞争结合NC41抗体。该scFv与三个活性抗原结合位点形成稳定的三聚体，用于结合NC41 Fab片段。我们提出三聚体scFv可能是直接连接的V(H)-V(L)分子的首选构象，这与当V(H)和V(L)结构域通过5-10个残基的短柔性接头连接时形成scFv二聚体（双抗体）形成对比。BIAcore生物传感器结合实验表明，与单体15个残基连接的scFv相比，三聚体scFv由于亲和力作用，其结合亲和力有预期的增加。scFv三聚体亲和力的增加为成像和免疫治疗提供了优势。
