Characterization of a PEGylated protein therapeutic by ion exchange chromatography with on-line detection by native ESI MS and MS/MS
Characterization of a PEGylated protein therapeutic by ion exchange chromatography with on-line detection by native ESI MS and MS/MS
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DOI:
10.1039/c6an02041k
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发表时间:
2017-01-21
期刊:
影响因子:
4.2
通讯作者:
Kaltashov, I. A.
中科院分区:
文献类型:
--
作者:
Muneeruddin, K.;Bobst, C. E.;Kaltashov, I. A.
Detailed profiling of both enzymatic (e.g., glycosylation) and non-enzymatic (e.g., oxidation and deamidation) post-translational modifications (PTMs) is frequently required for the quality assessment of protein-based drugs. Challenging as it is, this task is further complicated for the so-called second-generation bio-pharmaceuticals, which also contain "designer PTMs" introduced to either enhance their pharmacokinetic profiles (e.g., PEGylated proteins) or endow them with therapeutic activity (e.g., protein-drug conjugates). Such modifications of protein covalent structure can dramatically increase structural heterogeneity, making the very notion of "molecular mass" meaningless, as ions representing different glycoforms of a PEGylated protein may have nearly identical distributions of ionic current as a function of m/z, making their contributions to the mass spectrum impossible to distinguish. In this work we demonstrate that a combination of ion exchange chromatography (IXC) with on-line detection by electrospray ionization mass spectrometry (ESI MS) and methods of ion manipulation in the gas phase (limited charge reduction and collision-induced dissociation) allows meaningful structural information to be obtained on a structurally heterogeneous sample of PEGylated interferon beta-1a. IXC profiling of the protein sample gives rise to a convoluted chromatogram with several partially resolved peaks which can represent both deamidation and different glycosylation patterns within the protein, as well as varying extent of PEGylation. Thus, profiling the protein with on-line IXC/ESI/MS/MS allows it to be characterized by providing information on three different types of PTMs (designer, enzymatic and non-enzymatic) within a single protein therapeutic.