73
Figure 4. The empty capsid of eVLP (left) compared to the infectious particle fi lled with the RNA genome (lilac, right).
Professor George Lomonossoff said “The structural studies show that the extension acts like a dab of ‘molecular glue’ to stabilise the capsid subunits as they are pieced together. Thanks to these wonderful new images, we’ve now seen with our own eyes how the extension works, both in the infectious Cowpea Mosaic Virus and in our empty virus-like particle. This is a very important fi nding to validate our work on eVLPs – we now know that our engineered capsids are put together in the same way as CPMV and as a result we now have a new model for virus assembly. Because CPMV is a member of a large family of viruses that includes polio, foot-and-mouth and Hepatitis A, our studies should also aid our understanding of how these important animal viruses assemble.”
The research was enabled by recent advances in electron microscope hardware, in particular electron microscopes and direct electron detectors, also advances in image processing, sometimes collectively referred to as the “resolution revolution”. These advances have transformed the level of detail that can be revealed by cryo-EM. The structures of CPMV shown here are amongst the most detailed electron microscope structures of protein complexes yet published.
Figure 7. Researchers from the John Innes Centre (JIC) in Norwich. George Lomonossoff (Left), Yulia Meshcheriakova (Right) and Pooja Saxena (Second from right).
The University of Leeds, and Wellcome Trust, have recently invested £17 million in the new Astbury Biostructure Laboratory at the University of Leeds, which will be installing two state of the art electron microscopes and direct electron detectors in spring 2016.
More information about equipment arriving at the Astbury Biostructure laboratory can be found at
www.astbury.leeds.ac.uk/biostructurelaboratory.
*The research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) as part of the project entitled “Untangling the processes of replication and encapsidation in Picornavirales” led by Dr Neil Ranson at the University of Leeds and published in Hesketh et al, Nature Communications in December 2015. (Find the article at:
http://rdcu.be/fIIS).
Read, Share and Comment on this Article, visit:
www.labmate-online.com/articles
World’s Most Flexible AFM Released JPK is pleased to announce their latest AFM system, the world’s most fl exible AFM: the NanoWizard®
4 NanoScience AFM. The new NanoScience system again raises
the bar in terms of technical performance to deliver exciting new capabilities for users. It features a powerful fast scanning option delivering images every three seconds enabling users to track dynamic processes. Additionally, with the unique QI™ mode, quantitative imaging is possible with outstanding high resolution.
JPK have focused on providing users with easy, intuitive imaging capability with more modes and accessories than any other AFM system. Specifi cally, the NanoWizard® 4 NanoScience AFM provides unique solutions for mechanical and electrical sample characterisation delivering fl exible, advanced research capabilities to address the increasingly complex challenges faced by materials scientists today. The system employs the powerful digital Vortis™ controller to enable atomic resolution and fast scanning capabilities on a single platform. JPK’s QI™ mode (based on real force curves) gives the user unmatched force sensitivity and control to be able to handle any brittle, delicate, soft or sticky sample. The proven Ultra Speed scanner technology delivers three seconds per image performance for a 100 x 100 micron image area, performance that is thirty times faster than other AFMs with such a large scan range.
With the demand for increasing productivity and with more users wishing to perform long-running experiments over prolonged periods yet still being ‘in contact’ with them, JPK has added expanded usability and remote experimental control. The new ExperimentControl™ feature enables the user to both set up and control experiments via the Internet using their PC, tablet or smart phone. This delivers real time data allowing users to be in touch with their AFM 24/7.
The newly developed CryoStage option enables the user to control sample temperature from -120°C up to 200°C differentiating performance from regular ambient AFM systems. Additionally, the new StretchingStage can apply an external mechanical load to the sample, while the AFM measures variation of the sample properties in-situ. Furthermore, modules and modes for electrical measurements such as Conductive AFM (CAFM), Electrical Force Microscopy (EFM) and Kelvin Probe AFM (KPM-AFM) have been enhanced.
There is a new brochure available for downloading now. So, for more details about JPK’s NanoWizard® 4 NanoScience AFM system and its applications for the nano sciences, download the new brochure now.
37202pr@reply-direct.com
Temperature Controlled Stages in use at the University of Bristol to Assist in Endocytic Sorting Research
Linkam Scientifi c Instruments report on the use of their temperature controlled stages applied to CLEM and fl uorescence microscopy to assist in endocytic sorting in the School of Biochemistry at the University of Bristol.
Dr Paul Verkade is a Reader in Cell Imaging in the School of Biochemistry at the University of Bristol where he also heads the Electron Microscopy unit of the Wolfson Bioimaging Facility. His current research focus is to develop techniques and tools for the use of Correlative Light Electron Microscopy (CLEM) studying endocytic sorting.
Looking at his research in more detail, Dr Verkade discusses his work. “The research in my group focusses on intracellular segregation processes, especially in the endocytic system. In order to study these processes, we use a lot of live light microscopy to follow these dynamic events. However the resolution of the light microscope is too low to visualise certain aspects (e.g. recycling membrane tubules are about 50 nm in diameter). Thus we want to capture specifi c stages of the live imaging and analyse those in more detail in the electron microscope in so-called Correlative Light Electron Microscopy experiments. There are
several ways to perform those experiments and we use Linkam stages in two of those workfl ows.”
“In order to preserve the ultrastructure in its native condition, we have to freeze our samples very rapidly. We can then check the state and fl uorescence on these frozen samples using the Linkam CMS196 - Correlative Microscopy stage. If the sample is OK, we can then further process it, either using cryo TEM or more often perform freeze substitution and resin embedding. It would be interesting to mention that Linkam is very cooperative in making special adaptations, in our case modifying the grid cassette holder to accommodate thicker samples which we have acquired using High Pressure Freezing, rather than the standard EM grids.”
36842pr@reply-direct.com
WWW.LABMATE-ONLINE.COM
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84
