An engineered bivalent single-chain antibody fragment that increases antigen binding activity.

D Luo; M Geng; A A Noujaim; R Madiyalakan

doi:10.1093/oxfordjournals.jbchem.a021661

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An engineered bivalent single-chain antibody fragment that increases antigen binding activity.

D Luo·M Geng·A A Noujaim·R Madiyalakan

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Abstract

Bivalent single chain Fv (scFv) was constructed by fusing a polypeptide extension containing one or two cysteines to the COOH-terminus of an scFv antibody fragment. The scFv protein was expressed and secreted in a recombinant Pichia pastoris system as a dimer with a C-terminal disulfide bridge, as determined by Western blot analysis under non-reducing conditions. We found that the scFv construct with one cysteine in the C-extension (scFv-1Cys) exhibited a much higher dimer/monomer ratio than the two cysteine counterpart (scFv-2Cys). Binding activity measurements performed by means of a competitive radioimmunoassay showed that scFv-1Cys exhibited specific antigen binding activity, which was almost the same as that of the parental MAb, and approximately four- and fortyfold higher than those of the control scFv monomer and scFv-2Cys.

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Amino Acid Sequence Animals Antibodies, Bispecific Base Sequence Cysteine Dimerization Epitopes Humans Immunoglobulin Fragments Molecular Sequence Data Recombinant Fusion Proteins Journal Article Research Support, Non-U.S. Gov't

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D Luo, M Geng, A A Noujaim, R Madiyalakan. 1997. An engineered bivalent single-chain antibody fragment that increases antigen binding activity.. https://doi.org/10.1093/oxfordjournals.jbchem.a021661

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