Nanoparticles aid the microscopic detection of a protein relevant for cancer

June 16, 2014

Assemblies of proteins, known as protein complexes, have important functions in cells; protein complexes embedded in the cell membrane, for example, are responsible for the exchange with the extracellular environment. But because they are very small, 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 in their natural aqueous environment. The protein in question, the TRPV6 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 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.

Explore further: Putting light-harvesters on the spot

Related Stories

Putting light-harvesters on the spot

October 19, 2011

How the light-harvesting complexes required for photosynthesis get to their site of action in the plant cell is reported by RUB biologists in the Journal of Biological Chemistry. The team led by Prof. Dr. Danja Schunemann ...

Protein structure: Peering into the transit pore

February 7, 2014

The lipid-rich membranes of cells are largely impermeable to proteins, but evolution has provided a way through – in the form of transmembrane tunnels. A new study shows in unmatched detail what happens as proteins pass ...

Solving a complex protein problem

February 14, 2014

Many proteins undergo processing within cellular compartments called the endoplasmic reticulum and the Golgi apparatus. Transit between these structures is facilitated by transport vesicles, which bubble out from the membranes ...

Toxic injection with elastic band

February 24, 2014

Bacteria have developed many different ways of smuggling their toxic cargo into cells. Tripartite Tc toxin complexes, which are used by bacteria like the plague pathogen Yersinia pestis and the insect pathogen Photorhabdus ...

Recommended for you

Mathematicians identify limits to heat flow at the nanoscale

November 24, 2015

How much heat can two bodies exchange without touching? For over a century, scientists have been able to answer this question for virtually any pair of objects in the macroscopic world, from the rate at which a campfire can ...

New sensor sends electronic signal when estrogen is detected

November 24, 2015

Estrogen is a tiny molecule, but it can have big effects on humans and other animals. Estrogen is one of the main hormones that regulates the female reproductive system - it can be monitored to track human fertility and is ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.