Powder Diffraction Methods for Membrane Protein Structure Determination

Lead Research Organisation: Birkbeck, University of London
Department Name: Biological Sciences

Abstract

Membrane proteins comprise a large proportion of all the proteins coded by human and other eukaryotic genomes, and are the targets of more than one-half of all the pharmaceutical drugs marketed today. Knowledge of their three-dimensional structure is important for understanding how they function, and for the development of new drugs for the treatment of diseases. Protein X-ray crystallographic studies, which require well-ordered, large single crystals of the protein, provide such structural information. However, one of the major obstacles to membrane protein structure determinations currently is the ability to produce crystals of a size and quality suitable for single crystal studies. Although often many much smaller crystals can be produced, there has yet to be a method developed to utilise these for the determination of the structure of membrane proteins. The aim of this project is to develop both the methodology and tools necessary to determine the structure of membrane proteins based on samples not of single crystals, but of bunches of very small (microcrystals) using powder diffraction techniques.

Technical Summary

Membrane proteins comprise roughly one third of all the proteins coded by eukaryotic genomes, and are the targets of more than one-half of all currently marketed pharmaceuticals, although there is a relative dearth of crystal structures of this important class of proteins. A major obstacle to crystal structure determination is the ability to produce three-dimensional crystals of a size and quality suitable for single crystal structure determinations. Often, however, it is possible to produce showers of microcrystals which are not suitable for single crystals studies, and which resistant attempts to improve their size.
The aim of this project is the development of a method and associated tools for membrane protein structure determination based on powder diffraction of three-dimensional microcrystals.

Planned Impact

Membrane proteins comprise roughly one third of all the proteins coded by eukaryotic genomes, and are the targets of more than one-half of all currently marketed pharmaceuticals. However, the number of crystal structures that have been determined for membrane proteins greatly lags behind the number of structures that have been determined for soluble proteins. One of the major obstacles to structure determination is the ability to produce crystals of a size and quality suitable for single crystal determinations. Often, however, it is possible to produce showers of microcrystals, which are not suitable for single crystals studies, and which resistant attempts to improve their size. The development of a method for structure determination that could enable the use of powder diffraction on microcrystals would provide a significant benefit for both academic and industrial labs. Both the methodologies developed and the structures produced would be of particular value in pharmaceutical, insecticide, and food industries.
 
Description lead to crystal structures of ion channel published in high impact journals by another method

we also learned that this method is not the best one for membrane protein structure determination - it has been superceded by free electron lasers and cryoEM, and knowledge of this is valuable
Exploitation Route the structures we produced by crystallography have applications in pharmaceutical development
Sectors Pharmaceuticals and Medical Biotechnology

 
Description Pfizer Neusentis funding
Amount £20,000 (GBP)
Organisation Pfizer Ltd 
Department Neusentis Pfizer
Sector Private
Country United Kingdom
Start 05/2014 
End 01/2015
 
Description collaboration with Pfizer 
Organisation Pfizer Ltd
Department Neusentis Pfizer
Country United Kingdom 
Sector Private 
PI Contribution crystal structures and functional studies of sodium channel/drug complexes
Collaborator Contribution provided 0.5 funding for one year for postdoc and compounds for characterisation
Impact publications (see list)
Start Year 2014
 
Description crystallography and culture 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact technical advisor for development of dance performances and "in residence" talks for the public on women in crystallography

the opera is the basis for funding applications to arts agencies
Year(s) Of Engagement Activity 2014
URL https://www.youtube.com/watch?v=8d0rpEdCTac
 
Description international advisory board (australia) 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact international advisory board for scientific centre of excellence (australia)
Year(s) Of Engagement Activity 2008,2009,2010,2011,2012,2013,2014,2015,2016,2017
 
Description talk to 5th/6th form students and the general public on 100 years of crystallography 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Schools
Results and Impact talk to public and 5th/6th formers

students expressed interest in science
Year(s) Of Engagement Activity 2014