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Chaperone-Assisted Crystallography(CAC). Serdar Uysal University of Chicago, Department of Biochemistry and Molecular Biology ISFI. Outline. CAC concept and philosophy Chaperone scaffolds and phage display libraries HTP phage display library sorting CAC for high-hanging fruits.
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Chaperone-Assisted Crystallography(CAC) Serdar Uysal University of Chicago, Department of Biochemistry and Molecular Biology ISFI
Outline • CAC concept and philosophy • Chaperone scaffolds and phage display libraries • HTP phage display library sorting • CAC for high-hanging fruits
Chaperone-Assisted Crystallography (CAC) Several different chaperones
Molecular Scaffolds VH (Gtech) (U of C) (U of C + Gtech)
The Pipeline Chaperone Library Targets Soluble proteins, RNAs, membrane proteins Sorting Chaperone Production Crystallization & Structure Determination of Target-Chaperone Complex
Single Herceptin Fab Scaffold(i.e. no natural scaffold diversity allowed) 1L7I 1ZA3 2H9G 1TZI 1TZH 1S78
Synthetic Fab Libraries X=Y,S,G (50%) and equal mixture of remaining amino acids Why Y,S?
Library Sorting Pipeline 12 Targets in Parallel • • 1H NMR analysis ("simple targets) • Phage binding • • Biotinylation 1 week Target validation and prep automated sorting using a robot (3 rounds); Confirm success of sorting 1 weeks Transfer a mixture of clones to expression vector 1 week HTP protein production and BIAcore assay • Expression level • Affinity 1 week 6 chaperones for each target Total: 4 weeks
Fab clones for MCSG targets Targets provided by H. Li, F. Collart, and A. Joachimiak (MCSG)
Benchmarking the Fab CAC pipeline with 17 MCSG Targets Fellouse et al. JMB, in press
Crystal structureof FAB2-C209 (1.95 Å) Buried surface area: 1316 Å2 Jingdong Ye, Valya Tereshko, Joe Piccirilli
KcsA with Fab fragment Crystal lattice of the KcsA+ channel in complex with a proteolytic FAB fragment (PDB code 1k4c)
KcsA ? 8 binders produced
Res=3.7A° Rwork=34% Rfree=28%
C-terminal domain at 2.6A° 2X Binding Fab_10 4X Binding Fab_2
Conclusions • Synthetic libraries based on restricted AA diversity. • HTP pipeline for chaperone engineering. • High-affinity chaperones for membrane proteins, functional RNAs and protein complexes. • Novel structures using the CAC strategy.
The Univ of Chicago Tony Kossiakoff Shohei Koide Magda Bukowska Vince Cancasci Kaori Esaki Ryan Gilbreth James Horn Akiko Koide Brenda Leung James Raptis Valya Tereshko John Wojcik Jingdong Ye Valeria Vazquez Joe Piccirilli Eduardo Perozo Acknowledgments Genentech, Inc. Dev Sidhu Fred Fellouse Sara Birtalan Pierre Barthelemy UC Core Facilities Flow Cytometry Facility DNA sequencing Facility Advanced Photon Source/ANL Funding: NIH (NIGMS, NIDDK), HHMI, UC Cancer Research Center