In groundbreaking research, scientists have demonstrated the ability to strategically attach gold nanoparticles - particles on the order of billionths of a meter - to proteins so as to form sheets of protein-gold arrays. The nanoparticles and methods to create nanoparticle-protein complexes can be used to help decipher protein structures, to identify functional parts of proteins, and to "glue" together new protein complexes. Applications envisioned by the researchers include catalysts for converting biomass to energy and precision "vehicles" for targeted drug delivery.
The research, which was conducted at the U.S. Department of Energy's Brookhaven National Laboratory, will be published in the July 2, 2007 issue of the journal Angewandte Chemie.
"Our study demonstrates that nanoparticles are appealing templates for assembling functional biomolecules with extensive potential impact across the fields of energy conversion, structural biology, drug delivery, and medical imaging," said lead author Minghui Hu, a postdoctoral student working with James Hainfeld, Raymond Brinas, Luping Qian, and Elena Lymar in the Biology Department at Brookhaven Lab.
In the field of energy conversion, scientists have been searching for efficient ways to convert organic fuels such as ethanol into electricity using catalytic electrodes. But making single layers of densely packed enzymes, the functional part of such catalytic electrodes, has been a challenge. This new research shows that precisely engineered gold nanoparticles can be used to "glue" enzymes together to form oriented and ordered single layers, and that these monolayers are mechanically stable enough to be transferred onto a solid surface such as an electrode.
For this research, the scientists attached gold nanoparticles to an enzyme complex that helps drug-resistant tuberculosis bacteria survive, which has been studied by Brookhaven Lab biologist Huilin Li. The researchers suggest that gold nanoparticles might also be tailored to inactivate this enzyme complex, thereby thwarting drug-resistant TB - a research avenue they may explore in future studies.
In another part of the study, the researchers used proteins found on the surface of adenovirus, a virus that causes the common cold. Previous studies by Broookhaven's Paul Freimuth have characterized how this virus binds to the human cells it infects, and have suggested that modified forms of adenovirus could be used as vehicles to deliver drugs to specific target cells, such as those that make up tumors.
One key to this approach would be to enhance strong binding to the target cells. Toward that end, Hu and Hainfeld's group attached multiple viral proteins to the gold nanoparticles. Such constructs should have increased binding affinity for target cells and their larger size should extend blood residence time for improved drug delivery.
In another application, this new research showed that gold nanoparticles can enhance scientists' ability to decipher the structures and functionally important regions of protein molecules - the workhorses that carry out every function of living cells and whose dysfunction often leads to disease. With added nanoparticles, the "signal-to-noise ratio" and resolution of an imaging technique known as cryo-electron microscopy were significantly increased. This method might enable analysis of small biological macromolecules and complexes that are currently intractable to analyze by cryo-electron microscopy or x-ray crystallography.
Throughout this work, the biggest challenge was to synthesize size-controllable nanoparticles coated with organic molecules designed to react with specific protein sites. Hu explains the steps: "First, we design the specific interactions between gold nanoparticles and the proteins by coating the gold nanoparticles with functional organic molecules using a biocompatible linker. Then we add a genetically engineered sequence of peptides, called a "tag," to the protein molecule, which acts as the binding site for the gold nanoparticles. Finally, we incubate the nanoparticles with the protein solution to allow the nanoparticles and proteins to bind, transfer the solution onto a transmission electron microscopy grid, and analyze the complexes using state-of-the-art electron microscopes."
This research was funded by Brookhaven's Laboratory Directed Research and Development program, the Office of Environmental and Biological Research within the U.S. Department of Energy's Office of Science, and by the Institute of General Medical Sciences within the National Institutes of Health. Collaborators on the research include: Huilin Li, Guiqing Hu, Yanbiao Zhang, and Paul Freimuth, all from the Biology Department at Brookhaven, and Joseph Wall, Martha Simon, Beth Lin, and Frank Kito of the Brookhaven Lab scanning transmission electron microscope (STEM) team.
Karen McNulty Walsh | EurekAlert!
A room with a view - or how cultural differences matter in room size perception
25.04.2017 | Max-Planck-Institut für biologische Kybernetik
Studying a catalyst for blood cancers
25.04.2017 | University of Miami Miller School of Medicine
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Earth Sciences
25.04.2017 | Life Sciences
25.04.2017 | Earth Sciences