Assemblies of proteins, known as protein complexes, have important functions in cells; embedded in the cell membrane, for example, they are responsible for the exchange with the extracellular environment.
Their composition from subunits can only be determined indirectly or with extreme time-effort. Scientists at the INM – Leibniz Institute for New Materials are currently developing a novel microscopy technology for the direct detection of such individual subunits of protein complexes in the cell membrane of intact cells.
The methodology is applied to investigate a protein complex acting as a calcium channel in the cell membrane. The channel plays an important role in prostate cancer.
With the new analytical technique, the scientists employ electron microscopy to examine protein complexes in whole cells in their natural aqueous environment. The protein in question, the TRPV6 calcium channel forming protein, is first provided with an “anchor” to which a gold nanoparticle can bind. Each nanoparticle thus shows the position of a protein subunit so that the composition of the channels from a multiple of proteins and their locations become visible as they are in the living cell.
The cells are examined in tiny liquid chambers using the electron microscope. “Liquid specimens cannot be studied with traditional electron microscopy”, explains Professor Niels de Jonge, head of the Innovative Electron Microscopy group at the INM. Cells are typically studied in dry state via thin sectioning of solid dried plastic embedded or frozen material, which means that the proteins are no longer in their intact and natural environment. Using tiny liquid chambers the whole cells can now be examined in an aqueous environment. The chambers are made from silicon microchips and have very thin, electron transparent silicon nitride windows.
Research by the electron microscopy experts at the INM is focussing on two aims: “We are keen to perfect our new technology and demonstrate that its application is useful for biological and pharmaceutical research.” Researchers at the INM are therefore working closely with scientists from the Clinical and Experimental Pharmacology and Toxicology Department at the Saarland University.
Liquid STEM is an electron microscopy method developed by Niels de Jonge. STEM stands for Scanning Transmission Electron Microscopy, a microscopy modality in which a sample is raster scanned by an electron beam and electrons transmitted through the sample are detected. Liquid refers to the application of STEM for specimens in liquid.
Prof. Niels de Jonge
INM – Leibniz Institute for New Materials
Head Innovative Electron Microscopy
INM conducts research and development to create new materials – for today, tomorrow and beyond. Chemists, physicists, biologists, materials scientists and engineers team up to focus on these essential questions: Which material properties are new, how can they be investigated and how can they be tailored for industrial applications in the future? Four research thrusts determine the current developments at INM: New materials for energy application, new concepts for medical surfaces, new surface materials for tribological applications and nano safety and nano bio. Research at INM is performed in three fields: Nanocomposite Technology, Interface Materials, and Bio Interfaces.
INM – Leibniz Institute for New Materials, situated in Saarbruecken, is an internationally leading centre for materials research. It is an institute of the Leibniz Association and has about 195 employees.
Dr. Carola Jung | idw - Informationsdienst Wissenschaft
Coming to a monitor near you: A defect-free, molecule-thick film
27.11.2015 | University of California - Berkeley
Controlling Electromagnetic Radiation by Graphene
27.11.2015 | Universität Augsburg
Chemical weathering of rocks over geological time scales is an important control on the stability of the climate. This weathering is, in turn, highly dependent...
Before the fluid of the middle ear drains and sound waves penetrate for the first time, the inner ear cells of newborn rodents practice for their big debut. Researchers at Johns Hopkins report they have figured out the molecular chain of events that enables the cells to make “sounds” on their own, essentially “practicing” their ability to process sounds in the world around them.
The researchers, who describe their experiments in the Dec. 3 edition of the journal Cell, show how hair cells in the inner ear can be activated in the absence...
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
01.12.2015 | Event News
30.11.2015 | Event News
25.11.2015 | Event News
01.12.2015 | Earth Sciences
01.12.2015 | Life Sciences
01.12.2015 | Earth Sciences