Water's surface not all wet: Some water molecules split the difference between gas and liquid

 Air and water meet over most of Earth's surface, but exactly where one ends and the other begins turns out to be a surprisingly subtle question.

A new study in Nature narrows the boundary to just one quarter of water molecules in the uppermost layer -- those that happen to have one hydrogen atom in water and the other vibrating freely above.

Such molecules straddle gas and liquid phases, according to senior author Alexander Benderskii of the University of Southern California: The free hydrogen behaves like an atom in gas phase, while its twin below acts much like the other atoms that make up "bulk" water.

The finding matters for theoretical reasons and for practical studies of reactions at the water's surface, including the processes that maintain a vital supply of nitrogen, oxygen and carbon dioxide in the atmosphere.

"The air-water interface is about 70 percent of the Earth's surface," Benderskii said. "A lot of chemical reactions that are responsible for our atmospheric balance, as well as many processes important in environmental chemistry, happen at the air-water interface."

He added that the study provided a new way for chemists and biologists to study other interfaces, such as the boundary between water and biomembranes that marks the edge of every living cell.

"Water interfaces in general are important," Benderskii said, calling the study "an open door that now we can walk through and broaden the range of our investigations to other, perhaps more complex, acqueous interfaces."

In their study, Benderskii and his colleagues used techniques they invented to test the strength of hydrogen bonds linking water molecules (from the hydrogen of one molecule to the oxygen of another). These are the bonds that keep water a liquid at room temperature.

Specifically, the researchers inferred the bond strength by measuring the hydrogen-oxygen vibration frequency. The bond gets stronger as the frequency decreases, similar to the pull one feels when slowing down a child on a swing.

In the case of straddling molecules with one hydrogen in water, when compared to bonds below the surface, "the hydrogen bond is surprisingly only slightly weaker," according to Benderskii.

Likewise, the bond for the hydrogen atom sticking out of the water is similar in strength to bonds in the gas phase.

The researchers concluded that the change between air and water happens in the space of a single water molecule.

"You recover the bulk phase of water extremely quickly," Benderskii said.

While the transition happens in the uppermost layer of water molecules, the molecules involved change constantly. Even when they rise to the top layer, molecules for the most part are wholly submerged, spending only a quarter of their time straddling air and water.

The study raises the question of how exactly to define the air-water boundary.

If the straddling molecules constitute the boundary, it would be analogous to a wood fence where three of every four boards are missing -- except that since water molecules always are moving between submerged and straddling positions, the location of the fourth board would change millions of times per second.

If the boundary were the entire top layer of water molecules, the analogy would be a fence where one in four boards is sticking out at any one time.

A physical chemist, Benderskii began the study at Wayne State University in Detroit before joining the USC Dornsife College of Letters, Arts and Sciences in 2009 as an associate professor.

Benderskii's collaborators were lead author Igor Stiopkin, formerly at Wayne State and now at the University of Wisconsin-Madison; Champika Weeraman, also previously at Wayne State and now at Canada's National Research Council in Ottawa; Piotr Pieniazek and James Skinner of the University of Wisconsin-Madison; and Fadel Shalhout, formerly at Wayne State and now at USC Dornsife College.

The National Science Foundation and the U.S. Department of Energy funded the study.

Story Source:

The above story is reprinted (with editorial adaptations) from materials provided by University of Southern California. The original article was written by Carl Marziali.

Journal Reference:

Igor V. Stiopkin, Champika Weeraman, Piotr A. Pieniazek, Fadel Y. Shalhout, James L. Skinner, Alexander V. Benderskii. Hydrogen bonding at the water surface revealed by isotopic dilution spectroscopy. Nature, 2011; 474 (7350): 192 DOI: 10.1038/nature10173

Chemotherapy resistance: A new lead?

UA62784: that is the name of a molecule capable of preventing the proliferation of cancerous cells in vitro, and thus causing their cellular death. Its effects appear to amplify that of other anticancer agents currently used clinically, according to the work of the team headed by Ariane Abrieu, Inserm researcher at the Center de Recherche en Biochimie Macromoléculaire. This discovery could make it possible to overcome the phenomenon of resistance developed during certain chemotherapy treatments. The results are published in Chemistry and Biology on 26 May 2011.

Cancerous cells have the particularity of dividing in an uncontrolled manner. To prevent this happening, many of the anticancer drugs currently used clinically target microtubules. By destabilizing them, they block the division and thus the propagation of cancerous cells. However, these treatments are not effective on all cancers and, over time, come up against the phenomenon of resistance in certain tumors.

Sergey Tcherniuk, a member of Abrieu's team at the Centre de Recherche en Biochimie Macromoléculaire, has been able to demonstrate, in vitro, that the molecule UA62784 affects the way microtubules normally work. In fact, UA62784 blocks the division of cancerous cells, which for the main part causes cell death. Complementary experiments have shown that, when combined with other anticancer agents already used clinically in chemotherapy, UA62784 is able to boost their effect. Last but not least, effective doses of UA62784 are much lower than those administered with current medicines. Treating patients with this molecule could thus reduce the occurrence of chemotherapy resistance.

Although this discovery is still only at the experimental stage, it makes it possible to envisage significant advances in chemotherapy-based clinical treatments, not just for tumors that have been totally resistant until now, but also those liable to relapse. The researchers are currently conducting in vitro tests in order to collect further data on the efficacy of UA62784 and find out how to optimize its effect, coupled or not with other conventional anticancer agents.

More information: UA62784 is a cytotoxic inhibitor of microtubules, not Cenp-E. S.Tcherniuk, et al. Chemistry and Biology, 26 May 2011.

Provided by CNRS (news : web)

Chemistry with sunlight: Combining electrochemistry and photovoltaics to clean up oxidation reactions

The idea is simple, says Kevin Moeller, PhD, and yet it has huge implications. All we are recommending is using photovoltaic cells (clean energy) to power electrochemical reactions (clean chemistry). Moeller is the first to admit this isn't new science.

"But we hope to change the way people do this kind of chemistry by making a connection for them between two existing technologies," he says.

To underscore the simplicity of the idea, Moeller and his co-authors used a $6 solar cell sold on the Internet and intended to power toy cars to run reactions described in an article published in Green Chemistry.

If their suggestion were widely adopted by the chemical industry, it would eliminate the toxic byproducts currently produced by a class of reactions commonly used in chemical synthesis -- and with them the environmental and economic damage they cause.

The trouble with oxidation reactions

Moeller, a professor of chemistry in Arts & Sciences at Washington University in St. Louis, is an organic chemist, who makes and manipulates molecules made mainly of carbon, hydrogen, oxygen and nitrogen.

One important tool for synthesizing organic molecules -- an enormous category that includes everything from anesthetics to yarn -- is the oxidation reaction.

"They are the one tool we have that allows us to increase the functionality of a molecule, to add more "handles" to it by which it can be manipulated," says Moeller.

"Molecules interact with each other through combinations of atoms known as functional groups," he explains. "Ketones, alcohols or amines are all functional groups. The more functional groups you have on a molecule, the more you can control how the molecule interacts with others."

"Oxidation reactions attach functional groups to a molecule," he continues. "If I have a hydrocarbon that consists of nothing but carbon and hydrogen atoms bonded together, and I want to convert it to an alcohol, a ketone or an amine, I have to oxidize it."

In an oxidation reaction, an electron is removed from a molecule. But that electron has to go somewhere, so every oxidation reaction is paired with a reduction reaction, where an electron is added to a second molecule.

The problem, says Moeller, is that "that second molecule is a waste product; it's not something you want."

One example, he says, is an industrial alcohol oxidation that uses the oxidant chromium to convert an alcohol into a ketone. In the process the chromium, originally chromium VI, picks up electrons and becomes chromium IV. Chromium IV is the waste product of the oxidation reaction.

In this case, there is a partial solution. Sodium periodate is used to recycle the highly toxic chromium IV. A salt, the sodium periodate dissociates in solution and the periodate ion (an iodine atom with attached oxygens) interacts with the chromium, restoring it to its original oxidation state.

The catch is that restoring the chromium destroys the periodate. In addition, the process is inefficient; three equivalents of periodate is consumed for every equivalent of desired product produced.

Seeking cleaner byproducts

"All chemical oxidations have a byproduct, says Moeller, so the question is not whether there will be a byproduct but what that byproduct will be. People have starting thinking about how they might run oxidations where the reduced byproduct is something benign."

"If you use oxygen to do the oxidation, the byproduct is water, and that is a gentle process," he says.

But there is a catch. Like all other molecules, oxygen has a set oxidation potential, or willingness to accept electrons. "So whatever I want to oxidize in solution has to have an oxidation potential that matches oxygen's. If it doesn't, I might have to change my whole reaction around to make sure I can use oxygen. And when I change the whole reaction around, maybe it doesn't run as well as it used to. So I'm limited in what I can do," Moeller says.

A simpler idea is also cleaner.

There's another way to do it. "Electrochemistry can oxidize molecules with any oxidation potential, because the electrode voltage can be tuned or adjusted, or I can run the reaction in such a way that it adjusts itself. So I have tremendous versatility for doing things," says Moeller.

Moreover, the byproduct of electrochemical oxidation is hydrogen gas, so this too is a clean process.

But again there is a catch. Electrochemistry can be only as green as the source of the electricity. If the oxidation reaction is running clean, but the electricity comes from a coal-fired plant, the problem has not been avoided, just displaced.

The answer is to use the cleanest possible energy, solar energy captured by photovoltaic cells, to run electrochemical reactions.

"That's what the Green Chemistry article is about," says Moeller. "It's a proof-of-principle paper that says it's easy to make this work, and it works just like reactions that don't use photovoltaics, so the chemical reaction doesn't have to be changed around."

The next step

The Green Chemistry article demonstrated the method by directly oxidizing molecules at the electrode. No chemical reagent was used. Since writing the article, Moeller's group has been studying how solar-powered electrochemistry might be used to recycle chemical oxidants in a clean way.

Why would manufacturers choose to use a chemical oxidant, if the voltage of the electrode can be matched to the oxidation potential of the molecule that must be oxidized?

"An electrode selects purely on oxidation potential," Moeller explains. "A chemical reagent does not. The binding properties of the chemical reagent might differ from one part of the molecule to another. And there's also something called steric hindrance, which means that one part of the molecule might physically block access to an oxidation site, forcing substrates to other sites on the reagent."

"The chemistry community has learned how to use chemical reagents to make reactions selective," he says. "The reagents are usually expensive and toxic, so they are recycled," he says. "We are working on cleaning up reagent recycling."

In the chromium oxidation described above, for example, chromium IV could be recycled electrochemically instead of through a reaction with periodate. Instead of periodate waste[consistent with description above where periodate consumed?], the reaction would produce hydrogen gas as the byproduct.

"Another example is an industrial process for carrying out alcohol oxidations that convert the alcohol group to a carbonyl group," says Moeller. This process uses TEMPO, a complex chemical reagent discovered in 1960. TEMPO is expensive so it is recycled by the addition of bleach. This regenerates the TEMPO but produces sodium chloride as a byproduct."

In small quantities sodium chloride is table salt, but in industrial quantities it is a waste product whose disposal is costly. Once again, the TEMPO can be recycled using electrochemistry, a process that produces hydrogen as the only byproduct.

"We can't make all of chemical synthesis cleaner by hitching solar power to electrochemistry," Moeller says, "but we can fix the oxidation reactions that people use. And maybe that will inspire someone else to come up with simple and innovative solutions to other types of reactions they're interested in."

Story Source:

The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Washington University in St. Louis.

Journal Reference:

Laura A. Anderson, Alison Redden, Kevin D. Moeller. Connecting the dots: using sunlight to drive electrochemical oxidations. Green Chemistry, 2011; DOI: 10.1039/C1GC15207F

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

The new kid on the block

In synthetic chemistry, ‘carbene’ species—compounds bearing a carbon atom with two unpaired electrons—have a ferocious reputation. Left uncontrolled, they will react with almost any molecule they meet. But by harnessing this vigor with transition metals, chemists can turn carbenes into powerful chemical transformation reagents. Now, Zhaomin Hou and colleagues from the RIKEN Advanced Science Institute in Wako report a new class of compounds that contain multiple carbene units in one extraordinary structure: a cube-shaped molecule stabilized by ligand-protected rare-earth metals.

Rare-earth metals hold more electrons within their atomic radii than most other elements, making them essential in high-tech devices such as superconductors and hybrid vehicle batteries. Combining these metals with carbenes could lead to breakthrough procedures in synthetic chemistry. However, rare-earth metal–carbene complexes are usually unstable because the bonds they form are lopsided electronically, and therefore extremely reactive.

To overcome this problem, Hou and colleagues turned to a bulky ligand, based on a five-membered aromatic ring called cyclopentadiene (Cp´), which can trap rare-earth metal–carbene complexes into ordered solids. By mixing Cp´-protected lutetium (Lu) and thulium (Tm) rare-earth metal precursors with a carbon-donating aluminum reagent, they isolated a unique set of hybrid polyhedral crystals. X-ray analysis showed that these materials had a core of three rare-earth metals interconnected by six bridging methyl (CH3) groups.

An unexpected twist occurred when the researchers tested the thermal stability of the Lu– and Tm–methyl complexes. Heating to 90 °C caused the methyl groups to lose one of their hydrogen atoms, transforming them into carbenes. Then, after the elimination of a methane molecule, the crystal structure rearranged into a perfectly shaped cube featuring four Cp´-protected rare-earth metals and four carbene units (Fig. 1).

The team’s experiments revealed that the cubes spontaneously turned benzene–carbonyl molecules into alkenes by swapping their carbene groups for oxygen atoms, yielding a new oxygenated cube in the process. The researchers are now examining the reactivity of the cubes toward other molecules and plan to fine-tune the structure and reactivity of carbene compounds by investigating differently sized rare-earth metals together with different supporting ligands.

“This work demonstrates for the first time that methane can be eliminated rather easily from rare earth complexes containing methyl groups, affording structurally stable but highly reactive multi-carbene species,” says Hou. “Further studies along this line should open up a completely new frontier in rare-earth carbene chemistry.”

More information: Zhang, W.-X., et al. Ln4(CH2)4 cubane-type rare-earth methylidene complexes consisting of “(C5Me4SiMe3)LnCH2” units (Ln = Tm, Lu)., J. Am. Chem. Soc., 2011, 133 (15), pp 5712–5715
DOI: 10.1021/ja200540b

Provided by RIKEN (news : web)

A sweet defense against lethal bacteria

There is now a promising vaccine candidate for combating the pathogen which causes one of the most common and dangerous hospital infections. An international team of scientists from the Max Planck Institute of Colloids and Interfaces in Potsdam has developed a vaccine based on a carbohydrate against the Clostridium difficile bacterium, which is known to cause serious gastrointestinal diseases mainly in hospitals. The sugar-based vaccine elicited a specific and effective immune response in mice. Moreover, the scientists have also discovered strong indications that the substance can stimulate the human immune system to form antibodies against the bacterium.

Clostridium difficile bacterium can turn into a life-threatening condition: a highly virulent and antibiotic-resistant strain of the spore-forming pathogen Clostridium difficile bacterium appeared in the USA and certain Western European countries some eight years ago. Since then it has been posing a major risk for hospitalised patients, in particular, who are being treated with antibiotics or have a weak immune system, such as cancer or HIV patients. Whereas no more than four per cent of healthy humans have C. difficile in their gastrointestinal system, the bacterium colonises the intestines of 20 to 40 per cent of hospitalised patients. If other bacteria in the intestinal flora are repressed by antibiotics, the rod-shaped bacterium can reproduce extremely fast. It produces toxins which cause diarrhoea and gastrointestinal inflammation, often with a lethal outcome. Surviving patients require a very costly aftercare. This new, highly virulent pathogen can produce around 20 times more toxins and significantly more spores than previously identified pathogens.

However, a carbohydrate in the bacterial cell wall now provides the team of scientists led by Peter H. Seeberger at the Max Planck Institute of Colloids and Interfaces in Potsdam a “point of attack” for a potential vaccine. “Initial testing of the sugar-based antigen synthesised by the team has already produced very promising results”, says Peter H. Seeberger, Director at the Max Planck Institute in Potsdam.

The chemists in the team first developed a synthesis for the essential component of the antigen: the hexasaccharide. To assemble the oligosaccharide, they used four different monosaccharide building blocks. An efficient and convergent approach created the exact molecule with the required arrangement of the monosaccharides. “Synthesizing complex polysaccharides is still a challenge, not least because sugar molecules can bind in several different places”, Peter H. Seeberger says. However, the chemists were able to block other reaction sites so that they could exactly control where the original saccharides bound.

The scientists then conjugated the hexasaccharide to the CRM 197 protein, which is used in many vaccines, as sugar alone, as antigen, does not elicit an effective immune response. In order to defend itself successfully against a C. difficile infection, the immune system must also use another antigen. The chemical glycoprotein conjugate triggered a very effective immune response in two mice which were injected with the substance three times, at 2-week intervals. “The fact that mice are producing antibodies against the carbohydrates is in itself a success”, Peter H. Seeberger says. “Not all carbohydrates trigger the production of antibodies.” Furthermore, the antibodies produced by the mice bound exclusively to the sugar. Thus, the antigen cannot cause an autoimmune disease.

Additionally, the scientists proved that the antibodies developed against the hexasaccharide are also part of the human immune response; in the stool of hospital patients infected with C. difficile, they found antibodies against the sugar. “We can therefore expect to see that the human immune system produces antibodies against the sugar when vaccinated”, Seeberger concludes. What is more, “since the natural sugar already elicits the production of a small number of antibodies, we hope that the synthetic glycoprotein conjugate will trigger a more effective response.”

The vaccine candidate must now be subjected to further testing. First, it must be established whether it can effectively prevent infection in animals. “If these tests are successful, it will probably still take one or two years before the vaccine is tested on humans”, explains Peter H. Seeberger.

The vaccine candidate against C. difficile does not contain the only immunologically effective sugar from Seeberger's laboratory. Together with his colleagues, the chemist is developing sugar-based vaccines against numerous pathogens. “The current work is therefore also a proof of the progress made in glycochemistry and glycobiology”, according to Seeberger, who was awarded the 2007 Körber European Science Award for his development of a sugar synthesiser. The number of biological sugar molecules that can be produced by chemists in the laboratory is on the increase, which gives the biologists and medical scientists the opportunity to investigate their specific impacts. This fills Peter H. Seeberger with optimism: “These advances will lead to quantum leaps in related research areas, such as immunology, biology and medicine.”

More information: Matthias A. Oberli, et al. A Possible Oligosaccharide-Conjugate Vaccine Candidate for Clostridium difficile Is Antigenic and Immunogenic, Chemistry & Biology, 26 May 2011; DOI:10.1016/j.chembiol.2011.03.009

Provided by Max-Planck-Gesellschaft (news : web)

Walking microdroplets collect viruses and bacteria

A barely visible, electric field-controlled droplet moves on an appropriately prepared surface, harvesting viruses, bacteria and protein molecules deposited on it. This is how a novel method of collecting bioparticles looks like in real life. The method has been for the first time successfully tested by a team of researchers from the Institute of Physical Chemistry of the Polish Academy of Sciences and the French Institut d'Electronique, de Microélectronique et de Nanotechnologie and the Institut de Recherche Interdisciplinaire. The results of the tests have implications for the development of microsystems for chemical analyses, especially those dedicated to monitoring bioparticles present in the air.

Miniaturised devices designed to carry out reactions and chemical analyses are often heralded as the future of chemistry. The fabrication of such systems, popularly called "labs on chip," is seriously challenging engineers. "You can make an excellent microfabricated analytical system, but to make it work you still have to prepare the sample in a proper way," says Dr Martin Jönsson-Niedziółka from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS), adding: "Assume we have viruses and bacteria on a surface. Would we try to simply wash the surface with water, and then introduce a droplet of that water into a microanalyser, the result would be poor. Just because the concentration of the pollutants will be too low."

To ensure the highest possible concentration of bioparticles, it is better to use a small water droplet, just a microliter in volume. Such a droplet is introduced between two plates: a lower one with pollutant particles earlier deposited electrostatically, and a top one, coated with a system of small electrodes and an insulating layer (protecting against current flow through the droplet, which could lead to electrolysis). By making use of a phenomenon called electrowetting and applying voltage in a proper way, the droplet can be precisely displaced over the surface and so collect bioparticles from the entire plate. An additional advantage of the method is that the sample collected is already in the liquid state as required by many measurement methods. Moreover, as the displacement of the microdroplet is easy to control, the problem of how to deliver the sample to further lab-on-chip components disappears.

The systems with microdroplets have been fabricated and tested for a couple of years. A group of researchers from the Institute of Physical Chemistry of the PAS (Dr Martin Jönsson-Niedziółka) and the French Institut d'Electronique, de Microélectronique et de Nanotechnologie (Dr Vincent Thomy) and the Institut de Recherche Interdisciplinaire (Dr Rabah Boukherroub) had doubts about the fact that all earlier reports on microdroplets described the collection of latex microspheres from the surface. These particles are used because they are easily available in various sizes and safe in tests. It was not clear if the microdroplets would equally efficiently collect real bioparticles, such as bacterial spores or viruses.

The study made use of a microdevice fabricated by the French group. The particles investigated in tests included inactive bacteriophage MS2 (virus that infects bacteria), Bacillus atrophaeus spores and OA (ovalbumin) proteins. The bioparticles were deposited on two different surfaces. One of them was a hydrophobic surface, coated with a substance that resembles Teflon. The other plate was fabricated using nanowires (1 micrometer long) and its hydrophobicity was close to that characteristic for the famous lotus leaves. Until now, such superhydrophobic surfaces were not studied in any microdevices making use of electrowetting.

In experiments with viruses, the type of surface they were deposited on did not have any significant effect on the microdroplet cleaning efficiency. The cleaning efficiency was 98-99% and was higher than that typical for latex particles (92-93%). Different results have been found, however, for spores and protein molecules. High cleaning efficiency was found here for superhydrophobic surface only (99 and 92%, respectively), whereas the corresponding figures for hydrophobic surface were distinctly lower (46% and 71%, respectively).

The findings published in the journal Lab on a Chip demonstrate that the surface cleaning efficiency using microdroplets strongly depends on both the type of collected particles and the hydrophobic properties of the surface. "Everyone who wants to collect efficiently various bioparticles using microdroplets should use superhydrophobic surfaces," sums up Dr Jönsson-Niedziółka.

Story Source:

The above story is reprinted (with editorial adaptations) from materials provided by Institute of Physical Chemistry of the Polish Academy of Sciences, via AlphaGalileo.

Journal Reference:

M. Jönsson-Niedziółka, F. Lapierre, Y. Coffinier, S. J. Parry, F. Zoueshtiagh, T. Foat, V. Thomy, R. Boukherroub. EWOD driven cleaning of bioparticles on hydrophobic and superhydrophobic surfaces. Lab on a Chip, 2011; 11 (3): 490 DOI: 10.1039/C0LC00203H

Scientists find way to block stress-related cell death

Scientists from the Florida campus of The Scripps Research Institute have uncovered a potentially important new therapeutic target that could prevent stress-related cell death, a characteristic of neurodegenerative diseases such as Parkinson's, as well as heart attack and stroke.

In the study, published recently in the journal ACS Chemical Biology, the scientists showed they could disrupt a specific interaction of a critical enzyme that would prevent cell death without harming other important enzyme functions.

The enzyme in question is c-jun-N-terminal kinase (JNK), pronounced "junk," which has been implicated in many processes in the body's response to stresses, such as oxidative stress, protein misfolding, and metabolic disorder. JNK also plays an important role in nerve cell survival and has become a target for drugs to treat neurodegenerative disorders such as Parkinson's disease.

In recent studies, JNK has been found to migrate to the mitochondria—the part of the cell that generates chemical energy and that is involved in cell growth and death. That migration, coupled with JNK activation, is associated with a number of serious health issues, including apoptosis or programmed cell death, liver damage, neuronal cell death, stroke and heart attack.

"Activated JNK migrates to the mitochondria in reaction to a stress signal," said Philip LoGrasso, professor in the Department of Molecular Therapeutics and senior director for drug discovery at Scripps Florida who led the study. "Once there, it amplifies the effects of reactive oxygen species that cause significant damage to the cell. We developed a small peptide that intervenes in JNK migration and blocks those harmful effects—specifically cell death."

LoGrasso noted that the team was able to block JNK mitochondrial interaction without harming any other important enzyme processes, such as JNK's impact on gene expression. These findings, LoGrasso said, suggest that this interaction could be exploited in the development of a new drug.

"The peptide we developed will never be a drug, but it is an important new investigative tool that we can use to selectively probe mitochondrial biology," he said. "Our hope is to produce a small molecule that can mimic the inhibitory effect of this peptide. If we can do that, we might be able to selectively inhibit JNK mitochondrial interaction and use it to treat a number of diseases."

More information: "Selective Inhibition of Mitochondrial JNK Signaling Achieved Using Peptide Mimicry of the Sab Kinase Interacting Motif-1 (KIM1)," http://pubs.acs.or … 21/cb200062a

Provided by The Scripps Research Institute (news : web)