Life Sciences and Chemistry

Meteorites could have sweetened the earliest life.

Sugar from space may have nourished the first life on Earth. Two meteorites contain a range of polyols, organic substances closely related to sugars such as glucose 1 .

George Cooper of NASA’s Ames Research Center in California and co-workers have found these compounds in the Murchison meteorite, which fell over the Australian town Murchison in 1969, and in the Murray meteorite, that fell to Kentucky in 1950.

The structure of one of the basic members of the cell-membrane water-channel family, a protein called aquaporin 1 (AQP1), has been determined to a resolution of 2.2 angstroms (22 billionths of a meter).

The structure reveals the elegantly simple means by which AQP1 can transport water through the cell membrane at a high rate while effectively blocking everything else, even individual protons, the nuclei of hydrogen atoms.

Biophysicist Bing Jap led a team from Lawrence Berkeley Nat

Enzymatic films for bioactive surfaces

We encounter them every day in laundry detergent, dishwashing liquid, or shower gel: surfactants – surface-active substances. Surfactants belong to a category of molecules called amphiphiles, molecular hermaphrodites consisting of a water-loving (hydrophilic) “head” and a water-hating (hydrophobic) “tail”. Most surfacants are small amphiphilic molecules. However, an international research team working with Roeland J. M. Nolte, University of Nijme

Without the help of fossils or any other record from the distant past, scientists have identified what they believe represents a common ancestor of all animals on Earth, a microscopic organism with key genetic traits that, until now, have been found only in true animals.
Writing in Tuesday’s Proceedings of the National Academy of Sciences, a team of scientists from the Howard Hughes Medical Institute at the University of Wisconsin-Madison reports the discovery of a key cell communication ge

Sloshing proteins help bacteria find their waists.

Chemical waves may help a bacterium to divide by pinpointing its middle, according to a new model of protein interactions 1 .

Bacteria such as Escherichia coli multiply by dividing. Bacterial division (called binary fission) is simpler than human cell division (mitosis). Human cells erect scaffolding to transport components to the two nascent daughter cells at either end; bacteria just pinch in two.

Using tiny rust-containing spheres to tag cells, scientists from Johns Hopkins and elsewhere have successfully used magnetic resonance imaging to track stem cells implanted into a living animal, believed to be a first.

In the December issue of the journal Nature Biotechnology, the research team report that the neuronal stem cells take up and hold onto the spheres, which contain a compound of iron and oxygen. The iron-laden cells create a magnetic black hole easily spotted by magnetic resonan