Structure of active β-arrestin-1 bound to a G-protein-coupled receptor phosphopeptide

Shukla AK, Manglik A, Kruse AC, Xiao K, Reis RI, Tseng WC, Staus DP, Hilger D, Uysal S, Huang LY, Paduch M, Tripathi-Shukla P, Koide A, Koide S, Weis WI, Kossiakoff AA, Kobilka BK, Lefkowitz RJ

Nature 2013 May;497(7447):137-41

PMID: 23604254


The functions of G-protein-coupled receptors (GPCRs) are primarily mediated and modulated by three …

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Generating conformation-specific synthetic antibodies to trap proteins in selected functional states

Paduch M, Koide A, Uysal S, Rizk SS, Koide S, Kossiakoff AA

Methods 2013 Mar;60(1):3-14

PMID: 23280336


A set of phage display sorting strategies and validation methodologies are presented that are capable of producing high performance synthetic antibodies (sABs) with customized properties. Exquisite control of antigen and conditions during the phage display selection process …

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Substance P derivatives as versatile tools for specific delivery of various types of biomolecular cargo

Rizk SS, Misiura A, Paduch M, Kossiakoff AA

Bioconjug. Chem. 2012 Jan;23(1):42-6

PMID: 22175275


The use of proteins or nucleic acids as therapeutic agents has been severely hampered by their intrinsic inability to cross the cell membrane. Moreover, common techniques for driving the delivery of macromolecules lack the ability to distinguish between healthy and …

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Mechanism of activation gating in the full-length KcsA K+ channel

Uysal S, Cuello LG, Cortes DM, Koide S, Kossiakoff AA, Perozo E

Proc. Natl. Acad. Sci. U.S.A. 2011 Jul;108(29):11896-9

PMID: 21730186


Using a constitutively active channel mutant, we solved the structure of full-length KcsA in the open conformation at 3.9 Å. The structure reveals that the activation gate expands about 20 Å, exerting a strain on …

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Allosteric control of ligand-binding affinity using engineered conformation-specific effector proteins

Rizk SS, Paduch M, Heithaus JH, Duguid EM, Sandstrom A, Kossiakoff AA

Nat. Struct. Mol. Biol. 2011 Apr;18(4):437-42

PMID: 21378967


We describe a phage display methodology for engineering synthetic antigen binders (sABs) that recognize either the apo or the ligand-bound conformation of maltose-binding protein (MBP). sABs that preferentially recognize the maltose-bound form of MBP …

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A portable RNA sequence whose recognition by a synthetic antibody facilitates structural determination

Koldobskaya Y, Duguid EM, Shechner DM, Suslov NB, Ye J, Sidhu SS, Bartel DP, Koide S, Kossiakoff AA, Piccirilli JA

Nat. Struct. Mol. Biol. 2011 Jan;18(1):100-6

PMID: 21151117


RNA crystallization and phasing represent major bottlenecks in RNA structure determination. Seeking to exploit antibody fragments as RNA crystallization chaperones, we have used an arginine-enriched synthetic …

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Characterization of engineered actin binding proteins that control filament assembly and structure

Brawley CM, Uysal S, Kossiakoff AA, Rock RS

PLoS ONE 2010 Nov;5(11):e13960

PMID: 21103060


BACKGROUND: Eukaryotic cells strictly regulate the structure and assembly of their actin filament networks in response to various stimuli. The actin binding proteins that control filament assembly are therefore attractive targets for those who wish to reorganize actin filaments and …

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Keeping signaling in check

Kossiakoff AA, Rizk S

Structure 2010 Mar;18(3):275-6

PMID: 20223207


Cytokine signaling is triggered by a hormone-induced receptor aggregation process. IL-13 employs an unconventional sequence of steps for assembling its signaling complex to trigger activation and for turning it off. Both these processes involve some unusual molecular recognition features, as discussed by Lupardus et al. …

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An engineered substance P variant for receptor-mediated delivery of synthetic antibodies into tumor cells

Rizk SS, Luchniak A, Uysal S, Brawley CM, Rock RS, Kossiakoff AA

Proc. Natl. Acad. Sci. U.S.A. 2009 Jul;106(27):11011-5

PMID: 19549879


We have developed and tested a robust delivery method for the transport of proteins to the cytoplasm of mammalian cells without compromising the integrity of the cell membrane. This receptor-mediated delivery (RMD) technology …

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Role of a salt bridge in the model protein crambin explored by chemical protein synthesis: X-ray structure of a unique protein analogue, [V15A]crambin-alpha-carboxamide

Bang D, Tereshko V, Kossiakoff AA, Kent SB

Mol Biosyst 2009 Jul;5(7):750-6

PMID: 19562114


We have used total chemical synthesis to prepare [V15A]crambin-alpha-carboxamide, a unique protein analogue that eliminates a salt bridge between the delta-guanidinium of the Arg(10) side chain and the alpha-carboxylate of Asn(46) at the C-terminus of the polypeptide chain. This salt …

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