A two‐dimensional protein map of Chinese hamster ovary cells

Profiling of host cell proteins by two‐dimensional difference gel electrophoresis (2D‐DIGE): Implications for downstream process development

“…The above pattern of CHO cell culture supernatant HCP distribution was visually different from that of the intracellular HCP examined in several previous studies (Baik et al, 2006(Baik et al, , 2008Champion et al, 1999;Kaufmann et al, 1999;Krawitz et al, 2006;Pascoe et al, 2007). The bias of CHO cell extracellular HCP toward acidic proteins has been reported previously (Wimmer et al, 1994).…”

“…However, this pattern was not consistently observed in previous studies of intracellular HCP. In one study, the intracellular HCP did not appear to bias significantly toward acid or basic in a pH 3-10 range (Krawitz et al, 2006), while others showed some degree of bias toward acidic proteins by visual inspection of published gel images (Champion et al, 1999;Van Dyk et al, 2003). The significant abundance differences observed for extracellular HCP species were also not a visually prominent feature in previous studies where intracellular HCP were examined (Baik et al, 2006(Baik et al, , 2008Champion et al, 1999;Kaufmann et al, 1999;Krawitz et al, 2006;Pascoe et al, 2007;Van Dyk et al, 2003).…”

Comprehensive tracking of host cell proteins during monoclonal antibody purifications using mass spectrometry

“…Second, it is crucial to minimize cell lysis during cell culture/harvest because this represents the major source of HCPs in harvest fluid 28,29 as well as the major source of HCP profile variability. 30 Third, effective oncolumn wash conditions, capable of disrupting HCP interactions Limited numbers of CHO cell proteins have been identified in prior reports, either based on MS analysis of 2D gel spots (e.g., references [13][14][15][16][17] or direct LC-MS of lysed cells. 18 In many cases, these correspond to some of the most abundant CCCF HCPs identified in this study (and thus these may be considered the tip of the iceberg), suggesting that we measurably improved the sensitivity of HCP identifications with our methodology.…”

“…To date, proteomics-based profiling of HCPs has been almost universally performed by highly resolving 2D gel electrophoresis followed by MS identification of excised spots, usually with the purpose of identifying proteins differentially expressed under specific conditions. [13][14][15][16][17] These approaches are inherently non-quantitative in an absolute sense, but can be used to make relative comparisons. Carlage et al 18 used direct liquid chromatography-mass spectrometry (LC-MS) analysis of lysed, trypsin-digestion Chinese hamster ovary (CHO) cells to identify nearly 400 proteins, with an emphasis on those differentially expressed as a function of cellular productivity.…”

Proteomic profiling of recombinant cells from large-scale mammalian cell culture processes

“…Additionally electrospray ionisation (ESI-MS/MS) techniques are capable of providing amino acid sequence information on peptide fragments of the parent protein (Mann et al 2001). A number of 2D electrophoresis maps containing the location of identified proteins have been generated for CHO cells (Naryzhny and Lee 2001;Hayduk et al 2004;Champion et al 1999) and NS0 cells (Smales et al 2004). …”