Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.52 (PNGase F)
 1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Glycosylation which plays a crucial role in the pharmacological properties of therapeutic monoclonal antibodies (MAbs) is influenced by several factors like production systems, selected clonal population and manufacturing processes. Efficient analytical methods are therefore required in order to characterize glycosylation at different stages of MAbs discovery and production. Three mass spectrometry (MS)-based strategies were compared to analyze N-glycosylation of MAbs either expressed in murine myeloma (NS0) or Chinese Hamster Ovary (CHO) cell lines, the two current main production systems used for therapeutic MAbs. First a top-down approach was used on intact and reduced MAbs by liquid chromatography coupled to an electrospray ionization-time of flight mass spectrometer (LC-ESI-TOF), which provided fast and accurate profiles of MAbs glycosylation patterns for routine controls. Secondly, after digestion of the antibody with the peptide N-glycosidase F (PNGase F) enzyme, released N-linked glycans were directly analyzed by electrospray ionization-tandem mass spectrometry (ESI-MS/MS) without any prior derivatization, which gave precise details on the structure of the most abundant glycoforms. Finally, a bottom-up approach on tryptic glycopeptides using a nanoLC-Chip-MS/MS ion trap (IT) system equipped with a graphitized carbon column was investigated. Data were compared to those obtained with a more classical C18 reversed phase column showing that this last method is well suited to detect low abundant glycoforms and to provide in one shot information regarding both the oligosaccharide structure and the amino acid sequence of its peptide moiety.
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PMID:The way forward, enhanced characterization of therapeutic antibody glycosylation: comparison of three level mass spectrometry-based strategies. 1867 11

Cardiac action potentials (AP) are produced by the orchestrated functions of ion channels. A slight change in ion channel activity may affect the AP waveform, thereby potentially increasing susceptibility to abnormal cardiac rhythms. Cardiac ion channels are heavily glycosylated, with up to 30% of a mature protein's mass comprised of glycan structures. However, little is known about how reduced glycosylation impacts the gating of hERG (human ether-a-go-go related gene) channel, which is partially responsible for late phase 2 and phase 3 of the AP. This paper integrates the data from in vitro experiments with in-silico models to predict the glycosylation modulation dynamics in hERG ion channels and cardiac electrical signals. The gating behaviors of hERG channels expressed in Chinese Hamster Ovary (CHO) cells were measured under four glycosylation conditions, i.e., full glycosylation, reduced sialylation, mannose-rich. and N-glycanase treated. Further, we developed in-silico models to simulate glycosylation-channel interactions and predict the effects of reduced glycosylation on multiscale cardiac processes (i.e., cardiac cells, 1-D and 2-D tissues). From the in-silico models, reduced glycosylation was shown to shorten the repolarization phase of cardiac APs, thereby influencing electrical propagation in cardiac fibers and tissues. In addition, the patterns of derived electrocardiogram show that reduced glycosylation of hERG channel shortens the QT interval and decreases the re-entry rate of spiral waves. This work suggests new pharmaceutical targets for the long QT syndrome and potentially other cardiac disorders.
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PMID:In-silico modeling of glycosylation modulation dynamics in hERG ion channels and cardiac electrical signals. 2440 18