Structural and functional characterization of a DARPin which inhibits Ras nucleotide exchange

DOI: 10.1038/ncomms16111

Authors: Sandrine Guillard (MedImmune) , Paulina Kolasinska-Zwierz (MedImmune) , Judit Debreczeni (AstraZeneca) , Jason Breed (AstraZeneca) , Jing Zhang (Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford) , Nicolas Bery (Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford) , Rose Marwood (MedImmune) , Jon Tart (AstraZeneca) , Ross Overman (AstraZeneca) , Pawel Stocki (MedImmune) , Bina Mistry (MedImmune) , Christopher Phillips (AstraZeneca) , Terence Rabbitts (Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, University of Oxford) , Ronald Jackson (MedImmune) , Ralph Minter (MedImmune)
Co-authored by industrial partner: Yes

Type: Journal Paper
Journal: Nature Communications , VOL 8

State: Published (Approved)
Published: July 2017
Diamond Proposal Number(s): 17180

Abstract: Ras mutations are the oncogenic drivers of many human cancers and yet there are still no approved Ras-targeted cancer therapies. Inhibition of Ras nucleotide exchange is a promising new approach but better understanding of this mechanism of action is needed. Here we describe an antibody mimetic, DARPin K27, which inhibits nucleotide exchange of Ras. K27 binds preferentially to the inactive Ras GDP form with a Kd of 4 nM and structural studies support its selectivity for inactive Ras. Intracellular expression of K27 significantly reduces the amount of active Ras, inhibits downstream signalling, in particular the levels of phosphorylated ERK, and slows the growth in soft agar of HCT116 cells. K27 is a potent, non-covalent inhibitor of nucleotide exchange, showing consistent effects across different isoforms of Ras, including wild-type and oncogenic mutant forms.

Journal Keywords: Biochemistry; Targeted therapies

Subject Areas: Biology and Bio-materials, Medicine, Chemistry


Instruments: I03-Macromolecular Crystallography , I04-Macromolecular Crystallography

Added On: 26/07/2017 10:43

Documents:
ncomms16111.pdf

Discipline Tags:

Non-Communicable Diseases Health & Wellbeing Cancer Biochemistry Chemistry Structural biology Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)