The eighth formula of light
Russian scientists have solved the mystery of the glow of Siberian worms
Scientists from IBH RAS (Moscow) and IBF SB RAS (Krasnoyarsk) for the first time in the last 25 years have deciphered the structure of a new luciferin – a key component of a new ATP-dependent bioluminescent system. This is now the eighth luciferin known to science. The discovery of the "eighth formula of light", as well as the study of the luciferase of the worm Fridericia heliota and the peculiarities of the functioning of its bioluminescent system, bring scientists closer to understanding the mechanisms of effective conversion of the energy of chemical bonds into light quanta.
The uniqueness of the new bioluminescent system and the participation in the reaction of the universal energy unit of life – ATP – makes this discovery promising for a wide range of analytical applications. The way to decipher the "eighth formula of light" was difficult and non-trivial. The research results are published in the prestigious scientific journal – Angewandte Chemie (Petushkov et al., A Novel Type of Luciferin from the Siberian Luminous Earthworm Fridericia heliota: Structure Elucidation by Spectral Studies and Total Synthesis). A detailed popular science report on the work is published on the IBH website.
Bioluminescence is the phenomenon of light emission by living organisms. Glow, for example, beetles (fireflies), bacteria, corals, jellyfish, mollusks, worms, fungi, fish and other organisms. The formation of light quanta occurs due to the chemical oxidation reaction of a small organic molecule – luciferin – under the action of an oxidizer (air oxygen) and a special enzyme – luciferase. Prior to this work, the structures of only seven natural luciferins were known, the last of which was deciphered more than a quarter of a century ago.
The phenomenon of bioluminescence has received wide practical application. Ecologists use it to monitor the environment, in medicine and pharmaceuticals bioluminescence is used for clinical analyses and in test systems to search for drugs. In biochemical studies, bioluminescence is used to visualize physiological processes occurring in cells and whole organisms, as well as to determine various analytes, primarily ATP. In genetic engineering research, the most reliable method to "see" the work of a protein is to "sew" luciferase to it and add luciferin to the cells.
In 1990, team members Valentin Petushkov and Natalia Rodionova discovered a new species of luminous worms in the taiga in the vicinity of Krasnoyarsk, which received the zoological name Fridericia heliota. These are small soil worms (body weight does not exceed 2 mg), which emit a bluish-green light in response to mechanical irritation.
In 2000, the same group conducted the first studies of the properties of a new bioluminescent system: its components – luciferin and luciferase - were isolated. To obtain the required amount of biomaterial, it was necessary to manually select several hundred thousand worms from the soil and process them!
In 2011, the work received the support of the megagrant of the Government of the Russian Federation. The project was headed by an outstanding scientist who has studied the phenomenon of bioluminescence for many years – Nobel laureate Osamu Shimomura. At this stage, a team of employees of the Institute of Bioorganic Chemistry of the Russian Academy of Sciences from Moscow joined the work – a Group of synthesis of natural compounds under the leadership of I.Yampolsky, as well as employees of the Laboratory of Biomolecular NMR Spectroscopy M.Dubinny and K.Nadezhdin.
In 2013, with the joint efforts of specialists in organic synthesis and nuclear magnetic resonance spectroscopy (NMR), the structure of a new luciferin was established using a record small amount of substance (only 5 micrograms – that's how much it was possible to isolate from the biomass of worms collected over several years). It turned out that luciferin is a peptide consisting of residues of the amino acid lysine, an unusual derivative of the amino acid tyrosine, as well as oxalic and gamma-aminobutyric acids. The proposed structure was confirmed by complete synthesis: synthetic luciferin turned out to be completely identical to the one isolated from worms.
The glow of Fridericia heliota and the structure of the new luciferin.
The discovered luciferin Friericia heliota has a chance to occupy its niche in the field of applied bioluminescence: it is simple in chemical synthesis, extremely stable (retains its activity for months in solution), and, unlike bacterial luciferin, is non-toxic.
"For the first time, Russian scientists have made a discovery in the world of bioluminescence – an area where there has been a lull in identifying new research directions over the past 25 years. The breakthrough was achieved thanks to grant support, which provided not only funding for the work, but also cooperation of scientists of different specialties into a single temporary team. Deciphering the structure of the new luciferin is an excellent result of our group. But this is not the end of the study, but only the beginning of a huge hard work, now in a competitive environment," comments project manager Ilya Yampolsky.
The main direction of further research of the team is to establish the amino acid sequence and recombinant production of a new F.heliota luciferase, an enzyme that catalyzes the bioluminescence reaction. It is also planned to establish the pathway of luciferin biosynthesis, isolate all the enzymes responsible for this and the genes encoding them. In the long term, this will allow the transfer of bioluminescence from worms to another eukaryotic organism.
Portal "Eternal youth" http://vechnayamolodost.ru23.04.2014