Publications by authors named "Robert L Dufield"

Article Synopsis
  • Amino acid sequence variation in protein therapeutics needs careful tracking during cell line and culture development to ensure product quality.
  • A collaborative team at Pfizer developed a reliable testing strategy over six years, utilizing next-generation sequencing (NGS) and amino acid analysis (AAA) to efficiently identify genetic mutations and misincorporations in mammalian cell clones.
  • By switching from mass spectrometry to NGS and AAA for routine monitoring, Pfizer improved efficiency and freed up resources for more detailed product quality assessments in the later stages of development.
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Article Synopsis
  • Trumenba is a vaccine for preventing meningococcal meningitis caused by Neisseria meningitidis serogroup B in individuals aged 10-25 in the USA, made up of two lipoproteins expressed in E. coli.
  • The vaccine induces strong bactericidal antibodies against various NmB isolates and is designed with stability-enhancing micelles formed from the self-association of the lipoproteins.
  • Research shows that the lipoproteins activate TLR2 in the immune system, and their structure includes key motifs that are essential for guiding future vaccine development and manufacturing.
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Obtaining sufficient amounts of pure glycoprotein variants to characterize their structures is an important goal in both functional biology and the biotechnology industry. We have developed preparative HIC conditions that resolve glycoform variants on the basis of overall carbohydrate content for a recombinant transferrin-exendin-4 fusion protein. The fusion protein was expressed from the yeast Saccharomyces cerevisiae from high density fermentation and is post-translationally modified with mannose sugars through O-glycosidic linkages.

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Apolipoprotein A 1 Milano (ApoA-1M), the protein component of a high-density lipoprotein (HDL) mimic with promising potential for reduction of atherosclerotic plaque, is produced at large scale by expression in E. coli. Significant difficulty with clearance of host cell proteins (HCPs) was experienced in the original manufacturing process despite a lengthy downstream purification train.

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We have shown how product associating E. coli host cell proteins (HCPs) OppA and DppA can be substantially separated from apolipoprotein A-I(Milano) (apo A-I(M)) using Butyl Sepharose hydrophobic interaction chromatography (HIC). This work illustrates the complex problems that frequently arise during development and scale-up of biopharmaceutical manufacturing processes.

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