Here is the latest American Chemical Society (ACS) Weekly PressPac from the Office of Public Affairs. It has news from ACS’ 34 peer-reviewed journals and Chemical & Engineering News.
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In a potential advance toward a male contraceptive pill and new treatments for infertility, researchers are reporting the identification of key biochemical changes that put sperm “in the mood” for fertilization. Their study, which addresses a long-standing biological mystery, appears in ACS’ Journal of Proteome Research, a monthly publication.
Mark Platt and colleagues note in the new study that sperm cannot fertilize an egg immediately after entering the female reproductive tract. Sperm must acquire this ability after undergoing an activation process called “capacitation.” Scientists have known for years that this process involves phosphorylation. That common biological modification causes cellular activities to be turned “on” by the addition of phosphate molecules to certain amino acids within proteins. However, the specific biochemical details have been a deep mystery.
Using laboratory mice, the researchers compared the extent of phosphorylation in both capacitated and noncapacitated sperm samples. They identified 44 peptides exhibiting differential phosphorylation, on 59 specific amino acids, suggesting that modification of these particular sites is essential for the capacitation process. The relative ratio of phosphorylation between the capacitated and noncapacitated samples were also reported, providing the first biochemical description of what puts sperm “in the mood.” - MTS
Journal: Proteome Research
Journal Article: “Use of Differential Isotopic Labeling and Mass Spectrometry To Analyze Capacitation-Associated Changes in the Phosphorylation Status of Mouse Sperm Proteins”
In a development that could help safeguard people against potential acts of terrorism involving ricin, two groups of scientists in Georgia and New York are reporting the development of faster, more sensitive tests for detecting the deadly poison. One can detect one billionth of a gram of toxin in a single droplet of fluid in just five minutes, the scientists say. Reports on the tests — the most sensitive to date for detecting ricin — appear in ACS' Analytical Chemistry, a semi-monthly journal.
The scientists note in the new studies that ricin, a ribosomal inactivating protein found in castor beans, is one of the agents most likely to be used in acts of aerosol or food-related bioterrorism. Ricin can be obtained easily and quickly causes death when inhaled or eaten in small amounts. There is no known antidote. Quantitation of ricin also has medical applications, since ricin immunoconjugates have been used as anticancer agents. Although earlier researchers have developed tests capable of identifying ricin by protein recognition methods, existing tests are generally slow, cumbersome, and inaccurate.
In one study, Vern Schramm and Matthew Sturm describe a new test that detects the presence of active ricin in any sample by measuring the release of adenine from specific ricin substrates. Ricin-catalyzed adenine release from ribosomes stops protein synthesis and is the mechanism of action of this deadly toxin. By coupling adenine release to light formation by firefly luciferase, scientists can visualize the presence of ricin by the simple detection of light. The test can detect nanogram (one-billionth of a gram) amounts of ricin in minutes, they note.
In the other, John Barr and Suzanne Kalb describe development of a highly selective three-part test that involves capturing the ricin protein using special antibodies, evaluating the enzymatic activity of the ricin protein by mass spectrometry, and identifying the ricin protein by its amino acid sequence through mass spectrometry. In laboratory tests using small amounts of ricin spiked into food and body fluids, including milk, apple juice, serum, and saliva, the scientists found that the test was highly specific and accurate in comparison to current tests. - MTS
Journal: Analytical Chemistry
Journal Article: “Detecting Ricin: A Sensitive Luminescent Assay for Ricin A-chain Ribosome Depurination Kinetics”
Journal Article: “Mass Spectrometric Detection of Ricin and its Activity in Food and Clinical Samples”
At a time when water supplies are scarce in many areas of the United States, scientists in Minnesota are reporting that production of bioethanol — often regarded as the clean-burning energy source of the future — may consume up to three times more water than previously thought. Their study is scheduled for the April 15 issue of ACS’ Environmental Science & Technology, a semi-monthly publication.
Sangwon Suh and colleagues point out in the new study that annual bioethanol production in the U.S. is currently about 9 billion gallons and note that experts expect it to increase in the near future. The growing demand for bioethanol, particularly corn-based ethanol, has sparked significant concerns among researchers about its impact on water availability. Previous studies estimated that a gallon of corn-based bioethanol requires the use of 263 to 784 gallons of water from the farm to the fuel pump. But these estimates failed to account for widely varied regional irrigation practices, the scientists say.
The scientists made a new estimate of bioethanol’s impact on the water supply using detailed irrigation data from 41 states. They found that bioethanol’s water requirements can be as high as 861 billion gallons of water from the corn field to the fuel pump in 2007. And a gallon of ethanol may require up to over 2,100 gallons of water from farm to fuel pump, depending on the regional irrigation practice in growing corn. However, a dozen states in the Corn Belt consume less than 100 gallons of water per gallon of ethanol, making them better suited for ethanol production. “The results highlight the need to take regional specifics into account when implementing biofuel mandates,” the article notes. - MTS
Researchers in California are reporting for the first time that metals are key ingredients that give the coatings of anchoring byssal threads of marine mussels their amazing durability. The study could lead to the design of next-generation coatings for medical and industrial applications, including surgical coatings that protect underlying tissues from abrasion and also life-threatening bacterial infections, the researchers say. Their study appears in ACS’ Langmuir, a bi-weekly journal.
In the new study, Herbert Waite and colleagues point out that many existing coatings are severely limited by the materials they cover. A rubber band dipped in molten wax is a good case in point. Once hardened at room temperature, the wax is several times harder and stiffer than the underlying rubber, but even moderate extension shatters the wax. Scientists have been trying for years to develop robust coatings for soft or delicate underlying materials. Until recently, however, scientists knew little about the chemical mechanisms that allow mussels to coat the tendon-like fibers in byssal threads with a material that is both hard and extensible.
The researchers conducted a detailed chemical analysis of the protective outer coating of the byssus in a common species of marine mussel. They found that removing iron and calcium from the coating resulted in a 50 percent decrease in hardness, demonstrating that these metals play a key role in maintaining its integrity. Further insights could lead to the development of futuristic coatings with optimal strength and flexibility for medical and industrial applications, they note. - MTS
Safer and more effective drugs to fight obesity appear to be around the corner, but researchers still await a complete understanding of the biological underpinnings of the complex disease, according to an article scheduled for the April 13 issue of Chemical & Engineering News (C&EN), ACS’ weekly newsmagazine. Obesity is a growing epidemic that affects more than 72 million people in the United States alone, according to the Centers for Disease Control and Prevention.
C&EN assistant editor Carmen Drahl notes in the magazine’s two-part cover story that, despite billions of dollars spent on obesity research, researchers still do not fully understand the mechanisms of the disease. This lack of understanding is behind the recent setbacks among several once-promising anti-obesity drugs, according to the article. These problems include a wide range of side effects such as heart valve defects, high blood pressure, and psychiatric symptoms such as depression and anxiety, the article notes.
But researchers have recently made inroads into why some of those setbacks occurred in the first place. These insights have led to the development of promising new drugs that are more targeted for key appetite-control receptors in the brain and elsewhere in the body, according to the article. As a result, these drugs pose a lower likelihood of side effects while promoting weight loss. However, the reasons behind some obesity drugs’ psychiatric side effects are not as clear cut, and researchers are still eager to learn more about how the brain controls food intake and how it communicates with the gut. “Obesity is so complex and so multi-factorial that it’s hard to find a silver bullet,” says one scientist involved in obesity drug development. “I think we’re just scratching the surface.”
CAS - Science Connections is a series of articles that showcases the value of CAS databases in light of important general-interest science and technology news. Ranging in topics from fruit flies to Nobel Prize winners, the CAS - Science Connections series points to the CAS databases for a more complete understanding of the latest news.
Jean-Michel Cousteau, noted explorer, film-producer and environmentalist, and Len Sauers, Ph.D., Vice President of Global Sustainability for The Procter & Gamble Company, are the featured keynote speakers at the upcoming 13th annual Green Chemistry & Engineering Conference in June in College Park, Md. The focus of this year’s conference, June 23-25 at the Marriott Inn and Conference Center, is on progress made toward research objectives identified in the National Academy of Sciences’ 2006 report, “Sustainability in the Chemical Industry: Grand Challenges and Research Needs.” Sauers will address the convention on June 24, Cousteau on June 25. For more information on the conference, please visit www.gcande.org.
More ACS News
PressPac information is intended for your personal use in news gathering and reporting and should not be distributed to others. Anyone using advance PressPac information for stocks or securities dealing may be guilty of insider trading under the federal Securities Exchange Act of 1934.
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 154,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
Journal: Chemical & Engineering News
Journal Article: “Weighing options: Obesity researchers assess what it will take to move forward in the wake of drug-trial setbacks”
This story will be available on April 13.