E.Coli Host Cells with Modified Phos/Psts Periplasmic Phosphate-binding Proteins, and Method of Manufacturing Recombinant Fabs

Abstract

The present invention provides an E. coli host cell expressing a recombinant antibody characterized in that the E. coli host cell has been genetically modified in order to change at least one physical property of one or more E. coli proteins which in the wild type co-purify with said recombinant antibody.

1 . An  E. coli  host cell comprising at least one genetic alteration that results in modification of at least one physical property of at least one endogenous protein that, when unmodified, co-purifies with a recombinant antibody expressed by the host cell, wherein said at least one endogenous protein is selected from Dipeptide binding protein (DppA), Maltose binding protein (MBP) and thioredoxin. 
     
     
         2 . The host cell of  claim 1  where the physical property of the endogenous protein that is modified is the isoelectric point, hydrophobicity or size. 
     
     
         3 . The host cell of  claim 2  where the physical property of the endogenous protein that is modified is the isoelectric point. 
     
     
         4 . The host cell of  claim 1  wherein the recombinant antibody is a Fab or a Fab′ fragment. 
     
     
         5 . A method of manufacturing a recombinant antibody comprising fermenting a host cell of  claim 1 .