Browsing by Subject "C40B40/02"

Now showing 1 - 3 of 3

Antibody selection methods using cell surface expressed libraries
(United States Patent and Trademark Office, 1999-02-02) George M. Georgiou; Board of Regents, The University of Texas System
The invention relates to novel competitive immunoassays that are useful in detecting and quantitatively measuring analytes down to the nanomolar range. The invention also includes methods of selecting antibodies from libraries of polypeptides expressed on a cell surface. In conducting immunoassays, anti-analyte antibody molecules are expressed on the surface of a bacterial cell and then used to bind with labeled analyte. Quantitation is performed by competitively displacing the bound labeled analyte with a known amount of analyte and measuring the label. The method is rapid and inexpensive and may be performed with readily available safe labeling reagents such as fluorescent compounds.
Combinatorial protein library screening by periplasmic expression
(United States Patent and Trademark Office, 2006-08-22) Brent L. Iverson; George M. Georgiou; Barrett R. Harvey; The Board of Regents of the University of Texas System
The invention overcomes the deficiencies of the prior art by providing a rapid approach for isolating binding proteins capable of binding small molecules and peptides. In the technique, libraries of candidate binding proteins, such as antibody sequences, are expressed in the periplasm of gram negative bacteria and mixed with a labeled ligand. In clones expressing recombinant polypeptides with affinity for the ligand, the concentration of the labeled ligand bound to the binding protein is increased and allows the cells to be isolated from the rest of the library. Where fluorescent labeling of the target ligand is used, cells may be isolated by fluorescence activated cell sorting (FACS). The approach is more rapid than prior art methods and avoids problems associated with the outer surface-expression of ligand fusion proteins employed with phage display.
Selection of bacterial inner-membrane anchor polypeptides
(United States Patent and Trademark Office, 2009-11-03) Brent L. Iverson; George M. Georgiou; Barrett R. Harvey; Ki Jun Jeong; Board of Regents, The University of Texas System
The invention overcomes the deficiencies of the prior art by providing a rapid approach for isolating polypeptides capable of anchoring heterologous polypeptides to a bacterial inner membrane. In the technique, libraries of candidate anchor polypeptides are expressed as fusions with a heterologous polypeptide that is capable of being detected when bound to the inner membrane. In bacteria expressing a functional anchor sequence, the heterologous polypeptide becomes bound to outer face of the inner membrane. Bacteria with the functional anchor sequence can be identified by removing the outer membrane to remove non-anchored heterologous polypeptide followed by detection of anchored heterologous polypeptide. Such bacteria may be detected in numerous ways, including use of direct fluorescence or secondary antibodies that are fluorescently labeled, allowing use of efficient techniques such as fluorescence activated cell sorting (FACS).