Proteomic Profiling of IgG1 Producing CHO Cells Using LC/LC-SPS-MS: The Effects of Bioprocessing Conditions on Productivity and Product Quality.

The biopharmaceutical market is dominated by monoclonal antibodies, the majority of which are produced in Chinese hamster ovary (CHO) cell lines. Intense cell engineering, in combination with optimization of various process parameters results in increasing product titers. To enable further improvements in manufacturing processes, detailed information about how certain parameters affect cellular mechanisms in the production cells, and thereby also the expressed drug substance, is required.

Quantitative DY-maleimide-based proteomic 2-DE-labeling strategies using human skin proteins.

Sensitive differential proteomic analysis is challenging and often limited by distinct labeling or tagging strategies. In this study, we have examined the sensitivity, linearity, and photophysical properties of novel protein labeling DY-maleimide dyes (DY-505-MAL, DY-555-MAL and DY-635-MAL). All MS compatible DY-maleimide dyes exhibited excellent emission spectra, high sensitivity, and high linearity, when applied to standard 1-DE protein analysis.

Inducible knockout mutagenesis reveals compensatory mechanisms elicited by constitutive BK channel deficiency in overactive murine bladder.

The large-conductance, voltage-dependent and Ca(2+)-dependent K(+) (BK) channel links membrane depolarization and local increases in cytosolic free Ca(2+) to hyperpolarizing K(+) outward currents, thereby controlling smooth muscle contractility. Constitutive deletion of the BK channel in mice (BK(-/-)) leads to an overactive bladder associated with increased intravesical pressure and frequent micturition, which has been revealed to be a result of detrusor muscle hyperexcitability. Interestingly, time-dependent and smooth muscle-specific deletion of the BK channel (SM-BK(-/-)) caused a more severe phenotype than displayed by constitutive BK(-/-) mice, suggesting that compensatory pathways are active in the latter.

Metalloproteomics in the molecular study of cell physiology and disease.

Physical and chemical stresses as well as metal-related diseases can disrupt the normal trafficking of metal ions. Moreover, homeostatic imbalance of such metal ions may modulate essential cellular functions (including signal transduction pathways), may catalyze oxidative damage, and may affect the folding of nascent proteins. Here we describe a new qualitative subproteomic method for the detection, isolation, and identification of metal-interacting proteins.