Articles tagged ”GingisKHAN”

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SmartEnzymes™ in Multiplexed Middle-Down MS for targeted structure analysis

 

 

 In a recent article by Srzentic et al. (2018) the authors present a multiplexed middle-down MS workflow with improved performance for targeted protein structure analysis. Using GingisKHAN for antibody digestion, the authors analysed the F(ab) subunits of a therapeutic mAb. By implementing spectral and transient averaging of mass spectra across several LC-MS experiments, the authors revealed valuable information on chain pairing in the mAb.

 

To make the analysis, the therapeutic mAb trastuzumab was digested above the hinge using the GingisKHAN enzyme to generate intact F(ab) subunits. Intact myoglobin was subjected to analysis in a top-down MS approach to benchmark the workflow. The GingisKHAN-generated F(ab) subunits were then analysed using the middle-down MS workflow to compare the performance of data averaging approaches.

 

The results show the performances of spectral and transient averaging for tandem mass spectra as separate software tools for structural protein analysis. The transient averaging provided the most extensive sequence coverage for the F(ab) subunits, followed by spectral averaging. Furthermore, utilizing the multiplexed middle-down MS workflow for subunit analysis, the authors detected low-abundance branched product ions revealing valuable information about the light and heavy chain connectivity.

 

GingisKHAN® (Kgp enzyme) is a cysteine protease that digests human IgG1 at a specific site above the hinge region. The enzyme generates intact Fc and Fab subunits in 60 minutes.

 
Learn more about GingisKHAN

 
Srzentic et al., 2018. Multiplexed Middle-Down Mass Spectrometry Reveals Light and Heavy Chain Connectivity in a Monoclonal Antibody

Sequence Analysis

Antibody Sequence Analysis using GingisKHAN® and FabRICATOR®

September 28, 2018 | Applications, References |

  In an article by Luca Fornelli & Kristina Srzentic et al. recently published in Analytical Chemistry the authors present a workflow for antibody sequence determination by combining top-down and middle-down LC/MS. The authors analyzed the therapeutic antibody rituximab in its intact and fragmented form, using FabRICATOR and GingisKHAN to generate antibody subunits. By combining the performance of multiple ion activation techniques and a new software tool with top-level and middle-level strategies, the authors achieved extensive sequence coverage and obtained valuable information on key quality attributes.

  Rituximab was fragmented using members of the SmartEnzymes™ family for the generation of various antibody subunits. GingisKHAN was used for generating intact Fc and Fab subunits by site-specific cleavage of IgG1 above the hinge region. In order to obtain antibody subunits Fc/2, Fd and LC the authors used FabRICATOR-digestion followed by reduction. The intact antibody and the antibody subunits were analyzed using reversed phase LC/MS coupled with three separate ion activation techniques, and analyzed using a new software tool for fragment ion deconvolution.

  The complementing features of the ion activation techniques provided high quality information for a low number of LC/MS experiments. The authors achieved sequence coverage equivalent to what is obtainable with bottom-up strategies. In addition, the authors were able to analyze quality attributes such as PTMs, chain pairing and intact antibody mass determination – properties otherwise lost after extended proteolysis. These results highlight the benefits of combining top-level and middle-level strategies for applications currently performed by bottom-level strategies.

GingisKHAN® (Kgp enzyme) is a cysteine protease that digests human IgG1 at a specific site above the hinge region. The enzyme generates intact Fc and Fab subunits in 60 minutes.

Learn more about GingisKHAN

Fornelli et. al., 2018. Accurate Sequence Analysis of a Monoclonal Antibody by Top-Down and Middle-Down Orbitrap Mass Spectrometry Applying Multiple Ion Activation Techniques.