A team of scientists working at the National Institute of Standards and Technology (NIST) and University of California, Irvine, recently developed a way to magnify them dramatically. Their work has helped illuminate the important role of cholesterol within this boundary between the cell and the outside world.
The multi-institutional team used tools at the NIST Center for Neutron Research (NCNR) to examine the membrane at more than 1,000 times the resolution offered by an optical microscope—the equivalent of magnifying the point of a needle to the size of a large building. This enabled an unprecedented look at the membrane, which—because it controls access to our cells—is a major target for many drugs."Drugs that affect pain sensation, heart rhythm, mood, appetite and memory all target proteins lodged in the cell membrane that function like little gates," says Ella Mihailescu of the Institute for Bioscience and Biotechnology Research, a joint institute of NIST and the University of Maryland. "Because membranes and their proteins are important to medicine, we would like a better picture of how the membrane functions—and not just a better snapshot. We want to see it move, as it does constantly in real life."
These lipid chains form a two-layer skin with the "heads" of the lipids facing outward toward the cell's exterior and interior and the "tails" intermingling on the inside of the cellular membrane. Cholesterol is known to be important for managing disorder in membranes. The team saw for the first time that when cholesterol is present, these tails line up in a tight formation, looking like a narrow stripe from which the lipid chains stretch outward—and producing the order that had been previously anticipated, but never shown directly. But without cholesterol, the tails go a bit wild, flapping around energetically and in some cases even pushing up toward their chains' heads.
Mihailescu says the findings hint that cholesterol may have profound consequences for the membrane's gatekeeper proteins, which are very sensitive to their environment. "The membrane and its proteins interact constantly, so we're curious to learn more," she says. "With this unique magnification technique, we can explore the cell membrane more effectively than ever possible, and we are now establishing a research program with the University of Maryland to do so in greater detail."
* M. Mihailescu, R. G. Vaswani, E. Jardon-Valadez, F. Castro-Roman, J. A. Freites, D. L. Worcester, A. R. Chamberlin, D. J. Tobias and S. H. White. Acyl-chain methyl distributions of liquid-ordered and -disordered membranes. Biophysical Journal, March 2011, Vol. 100, pp. 1455-62, DOI: 10.1016/j.bpj.2011.01.035.
Chad Boutin | EurekAlert!
Immune Defense Without Collateral Damage
23.01.2017 | Universität Basel
The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering