Scientists from the U.S. and China have found that the DNA molecule can contribute to the formation of nanoparticles strictly defined structure. A sequence consisting of one type of nucleotides, interacting with the gold particles, led to the emergence of structures of a certain form. But the combination of different chains of nucleotides gave the most interesting effects...

As we remember, the DNA molecule is a kind of matrix - information about what should be protein that is stored in it as sequences of four nitrogenous bases, called nucleotides. These nucleotides are complementary to each other - so, in the double chain opposite the Foundation by the name of adenine is always his "colleague" thymine, and guanine constantly "partners" cytosine. In most cases, the combination of each of the three elements corresponds to some of the amino acid composition of proteins (though there is a signal sequence, which serves team in the synthesis process).

When the cell needs a protein, double-stranded DNA "spliced" and on its basis is synthesized matrix intermediary, called messenger RNA. In its molecule has the same nitrogenous bases (only thymine there replaced with similar uracil, which in the DNA, but from bacteriophage PBS1, no one else), so RNA can safely go to the ribosome - a place where amino acids are going proteins. And already at this "combine" special substances read written information on it, on its basis will pick up all the necessary amino acids and will connect them with each other.

So, as you see, DNA really is a good example of a natural matrix. For a long time scientists thought that this unique molecule may help to gather only proteins. However, recently revealed that the matrix functions of the carrier of genetic information is much more versatile. In particular, DNA can help a variety of nanoparticles to acquire the desired structure.

There is this: when adding DNA molecules to nanoparticles this acid is associated with them in a selective manner, linking nanoparticles with each other. Linking is due to the fact that nanoparticles are usually charged, and a nitrogenous base. Using the property of opposite charges attract each other, organic "accessories" DNA and inorganic nanoparticles form a very interesting structure.

However, until now, scientists have not been able to understand the regularities of influence of DNA on the configuration of the nanoparticles. Simply put, it was unclear what the sequence of deoxyribonucleic acid contribute to the formation of beads, some of the blocks, some of stars, etc., But recently a group of researchers from the University of Illinois at Urbana and Champaign (USA) jointly with their colleagues from Tsinghua University (China) managed to find out, how the DNA determines a structure of metal nanoparticles, with which it interacts.

In a series of experiments, the researchers incubated prismatic gold nanoparticles with different DNA sequences. After the mixture was added to the recovery agent (it was hydroxylamine) and one gold salts in order began the process of building the structure of nanoparticles. His results were observed with the help of electronic microscopes as transmission (transmission), and scanning.

In the end, it turned out that each of the four nucleotides of DNA was responsible for the formation of strictly defined structures. Thus, a sequence that contains only adenine, interacting with gold, were created only for particles of round shape with a rough surface. But Timanova chain contributed to the creation of a six-pointed stars. If the cause was taken cytosine, the nanoparticles was obtained rounded, but with a smooth surface, gurinova same sequence initiated the appearance of hexagonal nanostructures.

But the most interesting was that the combination of any two types of nitrogenous bases (for example, adenine and thymine) created particles averaged form. In particular, when the researchers incubated just such a sequence, then the gold was formed in patterns resembling stars with rounded rays. And the connection of guanine with cytosine led to the emergence of structures similar to the balls with ribbed surface. Scientists believe that there is great scope for experimentation, as variants of combinations of nucleotides very, very much.

The authors are convinced that their discovery can be used for practical purposes. In fact, nanoparticles with verified by template DNA structure will be useful in heterogeneous catalysis, whose success often depends even on the fine structure of the surface of the catalyst. Also they can be used in Raman spectroscopy, where particles, adsorbed on the surface, sharply increase spectroscopic signals.

So, it turns out that DNA is indeed a universal matrix, able, on the basis of the enclosed information within it to transform not only alive, but also inanimate matter. The only question is how to read the information...