Novel solid-phase refolding method for preparation of scFv-immobilized polystyrene plates with high-antigen-binding activity.

In the present study, we demonstrated site-specific immobilization and solid-phase refolding of single-chain Fv antibodies on hydrophilic polystyrene (phi-PS) plates that was mediated by novel polystyrene binding peptides (PS-tags: RIIIRRIRR), which were originally isolated and optimized in previous studies. Three PS-tag-fused scFvs, namely scFv-PS, scFv-(PS), and scFv-PSII, which were over-expressed in the insoluble fraction of Escherichia coli cells were denatured and site-specifically immobilized onto hydrophilic PS plates in the presence of 0.5-4 M urea and 0.

Direct immobilization of functional single-chain variable fragment antibodies (scFvs) onto a polystyrene plate by genetic fusion of a polystyrene-binding peptide (PS-tag).

Single-chain Fv antibodies (scFv) genetically fused with polystyrene-binding peptides (PS-tags, (PS19-1; RAFIASRRIRRP, PS19-6; RIIIRRIRR)) were generated by recombinant Escherichia coli for direct and site-specific immobilization of scFv on polystyrene supports with high antigen-binding activity. PS-tag-fused scFvs (scFv-PS-tags) specific for human C-reactive protein (CRP) were successfully over-expressed as an inclusion body and were refolded using the batch-dilution method. When scFv-PS-tags were immobilized on a hydrophilic PS (phi-PS) plate in the presence of Tween 20, they showed high antigen-binding activity comparable to, or greater than, that of a whole monoclonal antibody (mAb) on a hydrophobic PS (pho-PS) plate, which has been the exclusive method for enzyme-linked immunosorbent assay (ELISA).

Efficient immobilization of a ligand antibody with high antigen-binding activity by use of a polystyrene-binding peptide and an intelligent microtiter plate.

A method for immobilization of ligand antibody to improve the efficiency and sensitivity of a sandwich enzyme-linked immunosorbent assay (ELISA) was investigated by the use of anti-TNF-alpha monoclonal antibody chemically conjugated with a polystyrene-binding peptide (PS-tag) and an intelligent microtiter plate with large surface area. We compared both adsorption and antigen-binding activity of the ligand antibody (mAb) and mAb with the PS-tag (mAb-PS-tag) on 3 different PS plates: a hydrophobic PS plate (PS-F-1 plate), a hydrophilic PS plate (PS-A plate), and an intelligent microtiter plate packed with PS beads (PS-E plate). Contact areas of the PS-E plate toward ligand antibody solutions were 7-fold larger than those of conventional PS-F-1 and PS-A plates and consequently, both mAb and mAb-PS-tag were efficiently immobilized on the surface of the PS-E plate due to the significantly enhanced surface area.

High biological activity of a recombinant protein immobilized onto polystyrene.

The adsorption characteristics of glutathione S-transferases (GST) genetically fused with polystyrene (PS)-binding peptides (PS-tags) on PS plates with increase in hydrophilicity were studied to clarify the mechanisms of the specific interaction between the PS-tag-fused protein and PS plates. GST fused with the PS-tag PS19 (RAFIASRRIKRP) preferentially interacted with hydrophilic PS plates, even in the presence of high concentrations of competitors such as Tween 20 and BSA. Both basic and aliphatic amino acids in the PS-tags were involved in the specific interaction of PS-tags with the surface of the hydrophilic PS plate.