Articles in the Category ”References”

Analytical Methods to Monitor Site-Specific ADC Generation with GlyCLICK®


Scientists at the University of Strasbourg and University of Geneva use innovative native MS and IM methodologies for analytical characterization of a site-specific ADC generated with the GlyCLICK technology.

 

Antibody-drug conjugates (ADCs) combine the benefits of tumor-targeting monoclonal antibodies with the cytotoxic effect of drug payloads covalently linked to the antibody. The ADC generation process has evolved from non-selective and uncontrolled conjugation in early generation products, to site-specific conjugation resulting in homogenous and well-defined ADCs. Conjugation at the antibody Fc glycan sites using the GlyCLICK technology has proven to be an attractive option for the generation of site-specific ADCs.
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Middle-up Analysis of Monoclonal Antibodies using FabRICATOR®


With their molecular specificity for biological targets, monoclonal antibodies (mAbs) have revolutionized the field of research and medicine. Due to numerous post-translational modifications causing heterogeneity in the structure of mAbs, a comprehensive characterization of the physiochemical properties is necessary to ensure the quality, efficacy and safety of mAb-based therapeutic drugs.
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FabALACTICA Facilitates the Structural Insight into SARS-CoV-2 Neutralizing Antibodies


The first steps of infection with SARS-CoV-2 is binding of a viral Spike protein to a host receptor angiotensin-converting enzyme 2 (ACE2), followed by fusion of viral and host membranes. Antibodies that block this interaction are emerging as early COVID-19 therapies, however, the neutralization potencies of the antibodies are less studied.
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Characterization of SARS-CoV-2 Receptor-Binding Domains using SmartEnzymes™


Scientists at Leiden University Medical Center (LUMC) present a multilevel mass spectrometry approach using SmartEnzymes for in-depth characterization of mammalian SARS-CoV-2 receptor-binding (RBD) domains.

 

The COVID-19 disease caused by the SARS-CoV-2 virus has affected more that 100 million individuals in the ongoing pandemic. The enveloped RNA corona virus contains three structural proteins in the membrane, including the heavily glycosylated spike protein carrying 22 N-glycosylation sites. The spike protein in turn consists of two subunits, S1 and S2, where the receptor-binding domain (RBD) of S1 directly interacts with the ACE2 receptor in the human respiratory tract and facilitates host cell entry. Considering the relevance of RBD glycosylation on ACE2 binding and recognition by neutralizing antibodies, the use of well-characterized S proteins is essential for continued research and development of diagnostic tools and vaccines.

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FabRICATOR in an Evaluation of Mobile-phase Additives for LC-MS Characterization of mAbs


Biopharmaceuticals, including monoclonal antibodies (mAbs), have become an important class of therapeutics. The manufacturing procedure of mAbs is complex, and many possible variants of a particular mAb can be generated as a result of enzymatical and chemical modifications. Some of these modifications are critical for the efficacy and safety of the therapeutic mAb and are known as critical quality attributes (CQAs). CQAs need to be thoroughly monitored to ensure the quality and safety of the therapeutic agent.

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Automated Biotransformation Analysis of ADCs using FabRICATOR

The development of antibody-drug conjugates (ADCs) has evolved from first generation formats prepared by random conjugation technologies to next generation ADCs generated by site-specific conjugation. While significant improvements in overall efficacy and safety is displayed by site-specific formats, bioanalysis remains challenging due to complex in vivo biotransformation events including deconjugation, linker-payload cleavage and payload metabolism.

 

In this work, scientists at Bristol-Myers Squibb describe the development of an automated and fast affinity capture method using a cartridge-based platform combined with LC-HRMS analysis for biotransformation assessment of site-specific ADCs.

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A Middle-up Approach using FabALACTICA for Characterization of Bispecific Antibodies

In recent years, bispecifics have gained popularity due to their therapeutic advantages over conventional IgG’s. In particular, the T-cell bi-specifics have received a great deal of attention due to their potential for improved efficacy. However, because of their complex TCB formats, there are multiple challenges associated with manufacturing and analysis of these type of biomolecules. A number of product and process related side products are formed which require close monitoring and identification. Moreover, the existence of various charge variants is common which can be challenging to fully characterize and understand.
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FabRICATOR used to Locate Modification Sites of IgG Caused by Reducing Agents

A charge heterogeneity is an unfavorable phenomenon observed for mAbs and is considered as a critical quality attribute since it can alter the efficacy and pharmacokinetics of biopharmaceuticals. Acidic and basic species of an IgG are due to various chemical modifications on the molecule. The origin of acidic species has previously been reported to be formed by deamidation, oxidation of side-chains, cysteinylation, glycosylation, glycation, sialylation and fragmentation while the basic species comes from C-terminal lysine clipping, pyro-glu cyclization, succinimide formation and aggregation. Scientists at Boehringer Ingelheim together with scientists at NMI at University of Tübingen recently published a study characterizing the root cause of charged species of an IgG1 mAb.

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C-terminal lysine clipping and Fc receptor binding using SmartEnzymes

February 19, 2021 | References |

Researchers at LFB Biotechnologies in Paris, France have carried out a thorough analysis and characterization of the impact of C-terminal lysine clipping to Fc-receptor binding using a range of SmartEnzymes from Genovis.

 

The scientists separated an IgG1 antibody using SCX separation and purified the fractions without C-terminal lysines K0, with 1 C-terminal lysine K1 and with both lysines intact K2. The purified fractions were characterized for any further differences using FabRICATOR digestion and middle-level analysis. This approached enabled the researchers to study multiple post-translational modifications such as charge variants, oxidations and Fc glycosylation in a simple and robust way. The characterization revealed that the lysine heterogeneity was the main differentiator and all other PTMs were distributed between the fractions.
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SmartEnzymes in Targeted Sequencing of Heavily Glycosylated IgA1

The use of IgG-based antibodies in various clinical fields have increased over that past decades, continuing the development of better biopharmaceuticals. The use of other immunoglobulins including IgA, characterized with the ability to recruit effector cells, is progressively being considered a useful alternative. The complexity of the heavily glycosylated IgA does however pose analytical challenges and no method currently exist that allows unraveling of the human repertoire of this subclass.

 

Scientists at Utrecht University present a mass spectrometry method using electron capture dissociation (EDC) to obtain sequence ladders of the variable regions on the heavily N- and O-glycosylated anti-CD20 IgA1 antibody. Using SmartEnzymes and a native top-down approach, the scientists compared the IgA1 antibody to its anti-CD20 IgG counterpart, and their Fabs.

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