Crystal structure of inhibitor-bound human MSPL that can activate high pathogenic avian influenza

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Abstract

Infection of certain influenza viruses is triggered when its HA is cleaved by host cell proteases such as proprotein convertases and type II transmembrane serine proteases (TTSP). HA with a monobasic motif is cleaved by trypsin-like proteases, including TMPRSS2 and HAT, whereas the multibasic motif found in high pathogenicity avian influenza HA is cleaved by furin, PC5/6, or MSPL. MSPL belongs to the TMPRSS family and preferentially cleaves [R/K]-K-K-R↓ sequences. Here, we solved the crystal structure of the extracellular region of human MSPL in complex with an irreversible substrate-analog inhibitor. The structure revealed three domains clustered around the C-terminal α-helix of the SPD. The inhibitor structure and its putative model show that the P1-Arg inserts into the S1 pocket, whereas the P2-Lys and P4-Arg interacts with the Asp/Glu-rich 99-loop that is unique to MSPL. Based on the structure of MSPL, we also constructed a homology model of TMPRSS2, which is essential for the activation of the SARS-CoV-2 spike protein and infection. The model may provide the structural insight for the drug development for COVID-19.

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  1. SciScore for 10.1101/2020.06.12.149229: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board Statementnot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Complex formation, crystallization, and data collection: The peptide inhibitor (decanoyl-RVKR-cmk) was purchased from Merck-Millipore and reconstituted in dimethyl sulfoxide (DMSO).
    Merck-Millipore
    suggested: None
    Diffraction data were processed using the program iMosflm (31), followed by Aimless (32).
    iMosflm
    suggested: (iMosflm , RRID:SCR_014217)
    The model of SPD was manually fixed with COOT (34) and refined with Refmac5 (35).
    COOT
    suggested: (Coot, RRID:SCR_014222)
    All the structures in the figures were prepared using PyMOL (http://www.pymol.org/).
    PyMOL
    suggested: (PyMOL, RRID:SCR_000305)
    Homology modelling of TMPRSS2: The sequence alignment of the extracellular region of MSPL and TMPRSS2 was obtained using the BLAST webserver (https://www.uniprot.org/blast/).
    BLAST
    suggested: (BLASTX, RRID:SCR_001653)
    The homology model of TMPRSS2 was build using MODELLER (37).
    MODELLER
    suggested: (MODELLER, RRID:SCR_008395)

    Results from OddPub: Thank you for sharing your data.


    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.


    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.


    Results from JetFighter: Please consider improving the rainbow (“jet”) colormap(s) used on pages 25 and 22. At least one figure is not accessible to readers with colorblindness and/or is not true to the data, i.e. not perceptually uniform.


    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    About SciScore

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