Reports from Other Journals
Report from Nature by Sabine Heinhorst and Gordon Cannon
Photo by J. Jacobsen
Imagine doing chemistry with just seven atoms of an element! That is exactly how much of the short-lived radioactive seaborgium (Sg) scientists M. Schädel and colleagues had at their disposal to study element 106, twenty-three years after its discovery by Nobel laureate Glenn Seaborg (see article in the July 3 issue of Vol. 388, pp 55–57, and the News and Views commentary, pp 21– 22). Seaborgium’s weighty transactinide neighbors rutherfordium and hahnium have quite different chemical properties from their lighter homologues as a result of relativistic effects that lead to changes in the electron configuration of these heavy elements. Somewhat unexpectedly, Sg behaved similarly to the lighter group 6 elements molybdenum and tungsten with respect to the ability to form dioxydichlorides in the gas phase and SgO42- ions in aqueous solution. For further articles about transuranium elements and Glenn Seaborg, the reader may want to refer to J. Chem. Educ. 1989, 66, 379 and 1985, 62, 392 and 463. Have you ever wondered why eating really “hot” peppers gives you the sensation of burning pain? Caterina et al. (October 23 issue of Vol. 389, pp 816–824; and the News and Views commentary, p 783–784) have discovered that the
neurotoxin capsaicin, the “hot” compound in peppers, binds to a protein receptor in the membrane of certain sensory neurons that respond to noxious stimuli. The receptor, termed vanilloid receptor subtype 1 (VR1), is an ion channel which, upon binding of capsaicin, allows influx of mainly Ca2+ ions across the plasma membrane and into the cells. This, in turn, depolarizes the membrane potential, stimulates the neurons, and leads to signal transmission to the brain. Interestingly, like the chemical stimulus capsaicin, noxious heat can elicit the same response through activation of VR1. The authors suggest that this receptor might be involved in a general heat pain signal transduction pathway.
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Journal of Chemical Education • Vol. 75 No. 1 January 1998 • JChemEd.chem.wisc.edu
There seems to be no end to the types of reactions that RNA enzymes, commonly known as ribozymes, can catalyze. Tarasow and colleagues (September 4 issue of Vol. 389, pp 54–57) synthesized a pool of approximately 1014 RNA molecules with unique nucleotide sequences. Uridine nucleotides were pyridyl-modified and transition metals were included in the reaction to facilitate the desired carbon–carbon bond formation through a Diels–Alder cycloaddition. The RNA molecules were coupled to the diene substrate and subjected to 12 rounds of in vitro selection for the desired catalytic property. Eight independently selected families of catalytic RNA molecules were found that can speed up Diels–Alder reactions as much as 800-fold. These results lend further support to the assumption that the many different chemical reactions catalyzed by RNA molecules in a prebiotic “RNA world” generated the molecules crucial for the beginnings of life forms. This year’s Nobel prize in Physiology or Medicine went to Stanley Prusiner from the University of California, San Francisco (October 9 issue of Vol. 389, p 529). Prusiner’s pioneering work on prions, the presumed causative agents of such diseases as bovine spongiform encephalitis and Creutzfeldt–Jacob disease, has led to elucidation of the structural changes that turn an otherwise harmless cellular protein into a killer. A feature article in the October 23 issue (pp 795–798) by Aguzzi and Weissmann provides an excellent overview of prion research past, present, and future. In the same issue (p
771), the work of this year’s recipients of the Nobel prize for chemistry is summarized. Jens Skou (Aarhus University, Denmark), John Walker (Medical Research Council, Cambridge, UK), and Baul Boyer from the University of California, Los Angeles, share the prize for their work on biological energy conversion mechanisms. The physics prize recognizes work on ways to cool atoms below 1 K and trap them with light. It is shared by Steven Chu (Stanford University), Claude Cohen-Tannoudji (Collège de France and Ecole Normale Supérieure, Paris, France), and William Phillips of the National Institute of Standards and Technology, Maryland (p 770). Last, but not least: a new feature in Nature, which was introduced in the September 18 issue of Vol. 389, p 213 by editor Philip Campbell, might be interesting to readers who seek to draw connections between the sciences and other disciplines in their teaching. The first Art and Science article, by Martin Kemp, an art historian from Oxford University, features a discussion of Leonardo da Vinci’s Mona Lisa as it relates to the artist/scientist’s ideas about the intensity of light falling on a surface at different angles, the origin of helical patterns, and the dynamics of bodies of water on our planet (October 23 issue of Vol. 389, p 799). Sabine Heinhorst (heinhrst@ whale.st.usm.edu) and Gordon Cannon (
[email protected]) are in the Department of Chemistry and Biochemistry, University of Southern Mississippi, Hattiesburg, MS 39606-5043.
