Week In Science

A team of scientists headed by Robert Hazen, of the Geophysical Laboratory of the Carnegie Institution has developed new "protocols and procedures" for using DNA microarrays to rapidly identify mineral catalysts which pair well with abiotic building blocks of important biomolecules.

The idea is that certain abiotic molecules may combine readily in the presence of a mineral catalyst to perhaps form basic building blocks of biomolecules.

A DNA microarray allows vast numbers of experiments, which might take months to complete one by one, to be conducted simultaneously, essentially on an electronic chip wired to a computer for analysis.

Amino acids are one kind of biomolecule essential for life. Now certain types of amino acids can form naturally, and some forms are even found in interstellar molecular clouds. However living things use only one of two forms of such acids, a so-called left handed form. In non-living environments, they come in two kinds, a left and a right handed form.

Prof. Hazen showed in 2001 that left handed aspartic acid adhered preferentially to the left handed faces of the mineral calcite. This led researchers to believe that so-called chiral selection (chosing a left handed enantiomer preferentially to the right handed one, for example) could occur naturally with a non-living substrate.

Hazen has been working with Andrew Steele, also of the Carnegie Institute to develop a technology which simultaneously exposes minerals to numerous biological molecules to see what ones preferentially bind.

Hazen's team have been working with a team at the Smithsonian Institution led by Edward Vicenzi who are using Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) to identify which biomolecules and precursors adhere to which minerals used in the microarrays.

The DNA microarray technology speeds up the search for interesting pairings many times. This may lead to an increasing interest in the interface between inorganic and organic chemistry. In essence it combines the disciplines of chemistry, biology and geology, and may make for some interesting new discoveries.

More details can be found at:

PhysOrg.com.