Biochemistry Briefs

Photosynthesis incorporated into solar energy system

Researchers from the University of Tennessee, Knoxville and Massachusetts Institute of Technology have developed a solar collection system that mixes organic system with inorganic components. The results of the collaboration, led by Barry Bruce of UT, were published in Nature: Scientific Reports.

Taking key components of photosystem-I from blue-green algae, the researcher bioengineered a complex that can interact with a semi-conductor. Their semi-conductors, tubes composed of zinc-oxide, were designed to attract the complexes of photosystem-I components. The complex becomes excited when struck by sunlight, causing an electron to jump to an excited state and into the semiconducter, thus creating an electrical current.

Bruce has been recognized for his prior work on the subject, with the most recent mechanism proving to be much more efficient by orders of magnitude. While there is still a significant amount of ground the researchers have to cover before a feasible device can be developed, the researchers are optimistic that they can make rapid progress.

Breath analysis can detect early signs of disease

A new "breathalyzer" designed for metabolic changes can detect for early signs of disease, according to new work from the University of Wisconsin, Madison. Researchers were able to develop a method for detecting the ratio of carbon isotopes and determine whether glucose or protein is primarily being metabolized. Their results were published in the journal Metabolism.

Using a mouse model for polycystic ovary syndrome, researchers injected the mice with glucose that was labeled with radioactive isotope carbon-13. By comparing the ratio of carbon-13 to carbon-12 in the mice of the breath, the researchers were able to determine whether there were any differences in what the mice had metabolized within minutes. They measured this ratio using nuclear magnetic resonsense spectroscopy of blood serum samples and cavity ring-down spectroscopy for breath samples, the latter proving exciting for its noninvasiveness.

Normally, ingested sources of food is broken down as an energy source, but when someone is ill they will breakdown proteins in order to produce antibodies. This ratio can also be used to make quick diagnoses of other diseases, such as obesity, diabetes and cancer.

Mushrooms implicated in mysterious deaths

A research team led by Ji-Kai Liu recently discovered the culprit behind a series of unexplained deaths in China's Yunnan province: the little white mushroom Trogia venenata. Named after its discoverer, Zhu L. Yang, the fungus is responsible for the deaths of over 260 healthy people over the last 30 years. To support their hypothesis, scientists at the Kunming Institute of Botany and the Chinese Center for Disease Control and Prevention isolated and characterized three toxic compounds from the mushroom's fruiting bodies.

Using various spectroscopic techniques, the researchers identified gamma-guanidinobutyric acid, a known toxin, and two previously undiscovered amino acids. Structural analysis confirmed that both amino acids contained terminal ethynyl groups and a triple bond between two carbon atoms. The toxicity of the amino acids was further confirmed through trials with mice and blood analysis of an individual who died from consuming the mushroom.

Shortly after this discovery, a campaign was started to warn inhabitants of Yunnan of the dangers of consuming T. venenata. The campaign was very successful: no cases of "sudden unexplained death" have been reported since 2010.

Fluorescent protein aids scientific research

Chemists at North Carolina State University recently engineered a chemical label that can tag proteins of interest without disrupting their normal functions or the cells they inhabit. Alex Deiters, associate professor of chemistry, and Jason Chin, researcher at the Laboratory of Molecular Biology at the Medical Research Council in Cambridge, discovered a way to attach flurophores to a protein that is expressed in a mammalian cell.

Fluorescent proteins, which are twenty times larger than a flurophore, are chemistry's current badge maker. The flurophore's size gives it a major advantage, as fluorescent proteins are often large enough to disrupt the functions of their protein partners. To facilitate the flurophore's connection, Dieters and Chin synthesized a 21st amino acid and added it to cells that were designed to incorporate it into the proteins they wished to investigate. The amino acid lacked cellular components but possessed a special chemical handle that reacted only with a specifically designed flurophore.

According to the researchers, the reaction between the modified protein and the flurophore generated a high yield, required fewer reagents, and stably linked both reaction participants, presenting an effective means of studying previously inaccessible biological processes.