Identification of an Escherichia coli protein impurity in preparations of a recombinant pharmaceutical.
A host-cell protein impurity found in preparations of recombinant human acidic fibroblast growth factor (aFGF) was identified. Samples of aFGF examined by western blot analysis employing antiserum raised against an Escherichia coli cell lysate contained an immunoreactive protein with a molecular weight of approximately 26,000. The impurity was chromatographically isolated and the N-terminal sequence was determined. Comparing the sequence to a protein database provisionally identified the isolated impurity as the S3 ribosomal protein of E. coli. Monoclonal antibodies recognizing three separate epitopes of S3 confirmed the identity of the impurity in western blots of aFGF samples. The monoclonal antibodies were also used to estimate S3 levels in various preparations of aFGF.
O'Keefe
D O
DO
Department of Analytical Research, Merck Research Labortories, Rahway, New Jersey 07065.
DePhillips
P
P
Will
M L
ML
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins / Q000032:analysis* / Q000276:immunology; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination; D000939:Epitopes / Q000276:immunology; D004926:Escherichia coli / Q000276:immunology / Q000378:metabolism*; D016220:Fibroblast Growth Factor 1 / Q000032:analysis*; D006801:Humans; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000032:analysis; D012269:Ribosomal Proteins / Q000032:analysis / Q000276:immunology
D000911:Antibodies, Monoclonal; D001426:Bacterial Proteins; D000939:Epitopes; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; D016220:Fibroblast Growth Factor 1