Construction And Functional Identification Of Bispecific Nanobody For HER-2

In this study,a dual bispecific nanobody(BsNb)for human epidermal growth factor receptor 2(HER-2)was constructed.Seven different sequences of HER-2 antibodies were screened by phage library.These sequences were linked into the pET-28a high expression system and induced to express.After purification by nickel column high pressure protein chromatography,the purified protein was identified by antigen antibody interaction and antibody target cell binding.After identification,two antibodies with the highest binding activity were selected,and the corresponding fragments were inserted in pFUSE-CH and pFUSE-CL vectors to construct the humanized antibody expression plasmid.A double IgG epitope antibody was produced by cell expression,followed by cell killing test.Screening of highly specific nanoscale antibody fragments and successful construction of pET28a-BL21 soluble protein highly expressed strain were achieved.The humanized antibody expression vector was constructed,and the specificity of the bispecific nanobody was evident.The Humanized HER-2 nanobody has an obvious affinity and cytotoxicity to tumor cells.In comparison to other types of humanized antibodies,the humanized bispecific nanobody is an excellent alternative in terms of cost effectiveness and affinity.It will have a good prospect if industrialized.