Insulin synthesis without using E.coli

If living cell is replaced by a test-tube with DNA and a set of substances, it is possible to get proteins in a more simple and inexpensive way. That was done by Russian biochemists synthesising insulin without help of transgene Escherichia coli.

Insulin for diabetics has been obtained so far by utilising biotechnological synthesis. The basic material for the hormone - proinsulin protein - is obtained from transgene Escherichia coli, which is grown up in large quantities. However, Russian researchers have decided that it is too complicated to educe a single protein from an entire, although tiny organism, and invented a way to do without bacteria. Specialists of the Institute of Protein (Russian Academy of Sciences), Moscow State University and Institute of Bio-organic Chemistry decided to replace live bacteria by their extract and artificial reactor.

The reacting mixture, consisting of Escherichia coli extract, its transfer RNA, enzymes (that are in charge of manipulation with nucleic acids), amino acids and mineral salts were placed in a reactor. The matrix, from which proinsulin molecules were 'printed', was an artificially acquired plasmid - DNA molecule coding the sequence of amino acids in proinsulin.

Initially, a considerable part of synthesised protein precipitated in the reactor, which testifies to incorrect coagulation of a protein molecule. The researchers managed to avoid this by having changed reacting mixture volume, decreased temperature and concentration of bacterial extract.