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  1. Artikel ; Online: Retraction Note: A water-soluble DsbB variant that catalyzes disulfide-bond formation in vivo.

    Mizrachi, Dario / Robinson, Michael-Paul / Ren, Guoping / Ke, Na / Berkmen, Mehmet / DeLisa, Matthew P

    Nature chemical biology

    2024  Band 20, Heft 3, Seite(n) 392

    Sprache Englisch
    Erscheinungsdatum 2024-01-19
    Erscheinungsland United States
    Dokumenttyp Retraction of Publication
    ZDB-ID 2202962-X
    ISSN 1552-4469 ; 1552-4450
    ISSN (online) 1552-4469
    ISSN 1552-4450
    DOI 10.1038/s41589-024-01550-3
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  2. Artikel ; Online: Isolation of full-length IgG antibodies from combinatorial libraries expressed in the cytoplasm of Escherichia coli.

    Robinson, Michael-Paul / Jung, Jinjoo / Lopez-Barbosa, Natalia / Chang, Matthew / Li, Mingji / Jaroentomeechai, Thapakorn / Cox, Emily C / Zheng, Xiaolu / Berkmen, Mehmet / DeLisa, Matthew P

    Nature communications

    2023  Band 14, Heft 1, Seite(n) 3514

    Abstract: Here we describe a facile and robust genetic selection for isolating full-length IgG antibodies from combinatorial libraries expressed in the cytoplasm of redox-engineered Escherichia coli cells. The method is based on the transport of a bifunctional ... ...

    Abstract Here we describe a facile and robust genetic selection for isolating full-length IgG antibodies from combinatorial libraries expressed in the cytoplasm of redox-engineered Escherichia coli cells. The method is based on the transport of a bifunctional substrate comprised of an antigen fused to chloramphenicol acetyltransferase, which allows positive selection of bacterial cells co-expressing cytoplasmic IgGs called cyclonals that specifically capture the chimeric antigen and sequester the antibiotic resistance marker in the cytoplasm. The utility of this approach is first demonstrated by isolating affinity-matured cyclonal variants that specifically bind their cognate antigen, the leucine zipper domain of a yeast transcriptional activator, with subnanomolar affinities, which represent a ~20-fold improvement over the parental IgG. We then use the genetic assay to discover antigen-specific cyclonals from a naïve human antibody repertoire, leading to the identification of lead IgG candidates with affinity and specificity for an influenza hemagglutinin-derived peptide antigen.
    Mesh-Begriff(e) Humans ; Immunoglobulin G/genetics ; Cytoplasm ; Cytosol ; Biological Assay ; Escherichia coli/genetics ; Saccharomyces cerevisiae
    Chemische Substanzen Immunoglobulin G
    Sprache Englisch
    Erscheinungsdatum 2023-06-14
    Erscheinungsland England
    Dokumenttyp Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-023-39178-x
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  3. Artikel ; Online: A water-soluble DsbB variant that catalyzes disulfide-bond formation in vivo.

    Mizrachi, Dario / Robinson, Michael-Paul / Ren, Guoping / Ke, Na / Berkmen, Mehmet / DeLisa, Matthew P

    Publikation ZURÜCKGEZOGEN

    Nature chemical biology

    2017  Band 13, Heft 9, Seite(n) 1022–1028

    Abstract: Escherichia coli DsbB is a transmembrane enzyme that catalyzes the reoxidation of the periplasmic oxidase DsbA by ubiquinone. Here, we sought to convert membrane-bound DsbB into a water-soluble biocatalyst by leveraging a previously described method for ... ...

    Abstract Escherichia coli DsbB is a transmembrane enzyme that catalyzes the reoxidation of the periplasmic oxidase DsbA by ubiquinone. Here, we sought to convert membrane-bound DsbB into a water-soluble biocatalyst by leveraging a previously described method for in vivo solubilization of integral membrane proteins (IMPs). When solubilized DsbB variants were coexpressed with an export-defective copy of DsbA in the cytoplasm of wild-type E. coli cells, artificial oxidation pathways were created that efficiently catalyzed de novo disulfide-bond formation in a range of substrate proteins, in a manner dependent on both DsbA and quinone. Hence, DsbB solubilization was achieved with preservation of both catalytic activity and substrate specificity. Moreover, given the generality of the solubilization technique, the results presented here should pave the way to unlocking the biocatalytic potential of other membrane-bound enzymes whose utility has been limited by poor stability of IMPs outside of their native lipid-bilayer context.
    Mesh-Begriff(e) Bacterial Proteins/chemistry ; Bacterial Proteins/genetics ; Catalysis ; Disulfides/chemistry ; Genetic Variation ; Membrane Proteins/chemistry ; Membrane Proteins/genetics ; Models, Biological ; Protein Engineering ; Protein Folding ; Solubility ; Water/chemistry
    Chemische Substanzen Bacterial Proteins ; Disulfides ; DsbB protein, Bacteria ; Membrane Proteins ; Water (059QF0KO0R)
    Sprache Englisch
    Erscheinungsdatum 2017-06-19
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Retracted Publication
    ZDB-ID 2202962-X
    ISSN 1552-4469 ; 1552-4450
    ISSN (online) 1552-4469
    ISSN 1552-4450
    DOI 10.1038/nchembio.2409
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  4. Artikel: Mechanical heterogeneity in nanoscale films of liquid silica.

    Lacks, Daniel J / Robinson, Michael-Paul

    Physical review. E, Statistical, nonlinear, and soft matter physics

    2008  Band 77, Heft 4 Pt 1, Seite(n) 41504

    Abstract: Molecular dynamics simulations are carried out for slabs of silica liquid with thicknesses between 1 and 3 nm . A local analysis of the Born contribution to the elastic modulus, CB, shows that the elasticity is not uniform throughout the slabs--CB is ... ...

    Abstract Molecular dynamics simulations are carried out for slabs of silica liquid with thicknesses between 1 and 3 nm . A local analysis of the Born contribution to the elastic modulus, CB, shows that the elasticity is not uniform throughout the slabs--CB is identical to that of bulk silica in the slab interior, but CB is larger at the slab edges. The larger CB at the slab edges is due to a distinct atomic level structure characterized by larger density, larger concentration of more highly coordinated ions, and smaller silica rings.
    Sprache Englisch
    Erscheinungsdatum 2008-04
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1539-3755
    ISSN 1539-3755
    DOI 10.1103/PhysRevE.77.041504
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  5. Artikel ; Online: Fold catastrophes and the dependence of free-energy barriers to conformational transitions on applied force.

    Lacks, Daniel J / Willis, Joshua / Robinson, Michael-Paul

    The journal of physical chemistry. B

    2010  Band 114, Heft 33, Seite(n) 10821–10825

    Abstract: Applied mechanical force (f) can activate conformational change in molecules by reducing the height of a free-energy barrier (DeltaG(b)). In this paper, molecular dynamics simulations are carried out with umbrella sampling and self-consistent histogram ... ...

    Abstract Applied mechanical force (f) can activate conformational change in molecules by reducing the height of a free-energy barrier (DeltaG(b)). In this paper, molecular dynamics simulations are carried out with umbrella sampling and self-consistent histogram methods to determine free-energy profiles for a coarse-grained model of a protein under an applied force. Applied force is shown to cause fold catastrophes, where free-energy minima are destabilized until they disappear. It is well-known that a fold catastrophe at force f = B implies the scaling DeltaG(b) approximately |B - f|(3/2) in the limit of DeltaG(b) --> 0, but it is not clear whether this scaling is accurate for physically relevant barrier heights. The simulation results show that the fold catastrophe scaling is in fact accurate in the physically relevant regime and that the two-parameter function DeltaG(b) = A(B - f)(3/2) is superior to the two-parameter linear function for parametrizing changes in free-energy barriers with applied force.
    Mesh-Begriff(e) Biomechanical Phenomena ; Mechanical Phenomena ; Molecular Dynamics Simulation ; Protein Folding ; Protein Structure, Tertiary ; Thermodynamics
    Sprache Englisch
    Erscheinungsdatum 2010-08-26
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, U.S. Gov't, Non-P.H.S.
    ISSN 1520-5207
    ISSN (online) 1520-5207
    DOI 10.1021/jp106530h
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  6. Artikel ; Online: Efficient expression of full-length antibodies in the cytoplasm of engineered bacteria.

    Robinson, Michael-Paul / Ke, Na / Lobstein, Julie / Peterson, Cristen / Szkodny, Alana / Mansell, Thomas J / Tuckey, Corinna / Riggs, Paul D / Colussi, Paul A / Noren, Christopher J / Taron, Christopher H / DeLisa, Matthew P / Berkmen, Mehmet

    Nature communications

    2015  Band 6, Seite(n) 8072

    Abstract: Current methods for producing immunoglobulin G (IgG) antibodies in engineered cells often require refolding steps or secretion across one or more biological membranes. Here, we describe a robust expression platform for biosynthesis of full-length IgG ... ...

    Abstract Current methods for producing immunoglobulin G (IgG) antibodies in engineered cells often require refolding steps or secretion across one or more biological membranes. Here, we describe a robust expression platform for biosynthesis of full-length IgG antibodies in the Escherichia coli cytoplasm. Synthetic heavy and light chains, both lacking canonical export signals, are expressed in specially engineered E. coli strains that permit formation of stable disulfide bonds within the cytoplasm. IgGs with clinically relevant antigen- and effector-binding activities are readily produced in the E. coli cytoplasm by grafting antigen-specific variable heavy and light domains into a cytoplasmically stable framework and remodelling the fragment crystallizable domain with amino-acid substitutions that promote binding to Fcγ receptors. The resulting cytoplasmic IgGs—named 'cyclonals'—effectively bypass the potentially rate-limiting steps of membrane translocation and glycosylation.
    Mesh-Begriff(e) Antibodies ; Antibody Formation/genetics ; Bacteriophages/genetics ; Blotting, Western ; Cytoplasm/metabolism ; Electrophoresis, Polyacrylamide Gel ; Enzyme-Linked Immunosorbent Assay ; Escherichia coli/genetics ; Glycosylation ; Immunoglobulin G/biosynthesis ; Organisms, Genetically Modified/genetics ; Plasmids/genetics ; Protein Transport ; Surface Plasmon Resonance
    Chemische Substanzen Antibodies ; Immunoglobulin G
    Sprache Englisch
    Erscheinungsdatum 2015-08-27
    Erscheinungsland England
    Dokumenttyp Journal Article ; Research Support, N.I.H., Extramural ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ISSN 2041-1723
    ISSN (online) 2041-1723
    DOI 10.1038/ncomms9072
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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