In this work, two proteins, Z-domains and bovine casein, were autodisplayed on the outer membrane of the same Escherichia coli cells by co-transformation of two different autodisplay vectors. On the basis of SDS-PAGE densitometry, Z-domains and bovine casein were expressed at 3.12 × 105 and 1.55 × 105 proteins/E. Coli cell, respectively. The co-autodisplayed Z-domains had antibody-binding activity and the bovine casein had adhesive properties. E. Coli with co-autodisplayed proteins were analyzed by fluorescence assisted cell sorting (FACS). E. Coli with co-autodisplayed Z-domains and bovine casein aggregated due to hydrophobic interaction. For application to immunoassays, the Z-domain activity was estimated after (1) immobilizing the E. Coli and (2) forming an OM layer. E. Coli with co-autodisplayed two proteins that were immobilized on a polystyrene microplate had the same antibody-binding activity as did E. Coli with autodisplayed Z-domains only. The OM layer from the co-transformed E. Coli had Z-domains and bovine casein expressed at a 1:2 ratio from antibody-binding activity measurements.
All Science Journal Classification (ASJC) codes
- Cell Biology