Directed evolution of an anti-carcinoembryonic antigen scFv with a 4-day monovalent dissociation half-time at 37 degrees C.
An scFv has been engineered to bind carcinoembryonic antigen (CEA) with a dissociation half-time >4 days at 37 degrees C. Two mutations responsible for this affinity increase were isolated by screening yeast surface-displayed mutant libraries by flow cytometry. Soluble expression of the mutant scFv in a yeast secretion system was increased 100-fold by screening mutant libraries for improved yeast surface display level. This scFv will be useful as a limiting case for evaluating the significance of affinity in tumor targeting to non-internalizing antigens.
Graff
Christilyn P
CP
Department of Chemical Engineering and Biological Engineering Division, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Chester
Kerry
K
Begent
Richard
R
Wittrup
K Dane
KD
D002272:Carcinoembryonic Antigen / Q000276:immunology*; D019020:Directed Molecular Evolution; D006358:Hot Temperature; D007128:Immunoglobulin Fragments / Q000235:genetics* / Q000276:immunology; D010957:Plasmids
D002272:Carcinoembryonic Antigen; D007128:Immunoglobulin Fragments