The new technique, developed by a research team led by University of Illinois at Chicago assistant professor of chemistry Lawrence Miller, provides the clearest, most dynamic view yet of protein-protein interactions in cells when viewed through a specially modified microscope.
The finding is reported in the Proceedings of the National Academy of Sciences (advanced online July 19.)
Knowing where and when particular proteins interact within the cell is key to understanding life processes at the molecular level.
In a technique called luminescence resonance energy transfer, two proteins in a cell are labeled with differently colored, luminescent molecules that absorb light of one color and give it off as another color. By taking several pictures of the cell and mathematically analyzing the pictures, researchers gain information about the proteins' precise location and whether they are interacting.
Miller and his team used a novel type of luminescent molecule for labeling, making it possible to get the same information using fewer pictures. This simplifies the analysis and allows for five-fold faster data acquisition. Images show a 50-fold improvement in sensitivity.
Working with Jerrold Turner, professor and associate head of pathology at the University of Chicago, Miller used a hybrid chemical/genetic approach to tag the proteins of interest. One of the proteins was genetically modified so that it would bind to a terbium complex. The terbium complex has an unusually long time between light absorption and emission. The second target protein was genetically modified to link to a fluorescent tag with a short emission lifetime. When the two proteins interact, the luminescent tags are brought very close together, generating a unique luminescent signal that can be seen under a microscope.
Miller and his colleagues modified a conventional microscope to exploit the long lifetime of the terbium protein tags. Pulsed light is used to trigger the terbium luminescence, detected after the other luminescent species within cells have gone dark, allowing unwanted background to be removed from the image.
The new technique "increases sensitivity and makes the whole process faster," Miller said. "This increases the time-resolution of the experiment, allowing you to see how interactions change on a faster time scale, which can help to better figure out how certain biological phenomena work."
The technique required a reliable way to deliver the luminescent terbium probe through a living cell membrane without contaminating or damaging the cell. The researchers developed a way to co-opt pinocytosis, the process by which cells drink in small amounts of surrounding fluid.
"With this new tool, we hope cell biologists and others will be able to study things they haven't seen before, such as interactions that couldn't be visualized in live cells in real time," Miller said. "Hopefully the method will yield information that makes it easier to deduce biological mechanisms."
Other authors include UIC graduate students Harsha Rajapakse (the lead author), Nivriti Gahlaut and Shabnam Mohandessi and University of Chicago graduate student Dan Yu. The terbium tag was developed in collaboration with Richmond, Calif.-based Lumiphore, Inc. Major funding was provided by the National Institutes of Health and the Chicago Biomedical Consortium.
Paul Francuch | Newswise Science News
Zebrafish's near 360 degree UV-vision knocks stripes off Google Street View
22.06.2018 | University of Sussex
New cellular pathway helps explain how inflammation leads to artery disease
22.06.2018 | Cedars-Sinai Medical Center
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
22.06.2018 | Materials Sciences
22.06.2018 | Earth Sciences
22.06.2018 | Life Sciences