pHEN2 vector and construction of scFv C1-N1N2. A: Schematic representation of the pHEN2 phagemid vector (Griffin 1. library). pelB leader: signal peptide sequence of bacterial pectate lyase that mediates secretion into the periplasmic space; VH : variable fragment of the heavy chain; VL: light chain; 6xHis: 6 histidine-tag; myc: myc-tag; amber: amber stop codon; N1, N2, C-term: portions of the N- and C-term of phage capside protein pIII; LMB3 and pHENSeq: primers used for sequencing the VH and VL domain. B: Schematic construction of vectors encoding soluble scFv C1 and scFv C1-N1N2. The amber stop codon between the scFv and gene III in pHEN 2 was removed by mutagenesis (middle construct). The C-terminal portion of pIII was removed in the final pHEN C1-N1N2 vector (bottom construct), first by PCR amplification of pHEN C1-pIII, introducing an EcoRI site after N2, and subsequently by cloning the NcoI and EcoRI digested PCR product into the linearized pHEN C1-pIII plasmid at the NotI and EcoRI sites. H: 6 histidine-tag; M: myc-tag.