Increased yield and activity of soluble single-chain antibody fragments bycombining high-level expression and the Skp periplasmic chaperonin

The success of recombinant antibody fragments as diagnostic reagents and th erapeutic agents depends on the availability of sufficient functional mater ial. We have produced a bacterial expression vector that combines high-leve l expression driven by a modified Shine-Dalgarno sequence with the periplas mic chaperonin Skp. Using this vector, we are able to obtain higher yields of soluble antibody fragments from cultures without the need for supplement ation of the culture medium during expression. The fragments produced in th e presence of the Skp show improved antigen binding activity compared to wh en the chaperonin is absent. (C) 2001 Academic Press.