Biologists from the Russian Academy of Sciences Biotechnology Federal Research Centre – together with colleagues form the Institute of Biomedical Chemistry – noted that an enzyme from the hyperthermophilic archaeon, Thermococcus sibiricus, occurring in the Samotlor oil deposit in Khanty-Mansiysk region in Siberia at a depth of more than 2,000 metres could be safer than alternatives now used in therapy.
“For the first time, L-asparaginases as designated by the authors differs from well-known alternative analogues by virtue of its greater stability and selective toxicity towards cancer cells,” the research centre’s press office said. The results of the work can be found in the International Journal of Molecular Sciences.
L-asparaginases is an enzyme that accelerates amino acid cleavage into aspartic acid and ammonia. It is already used in therapy for certain types of tumour and even in the food industry. It was the first enzyme to be discovered to be active in acting against tumours and to be used clinically.
“Despite the demonstrated therapeutic effect, the asparaginases being used at this time has several shortcomings. As a result of serious side effects, decisions were often made not to use this preparation in cancer treatment,” said Maria Dumina of the group of fungal genetic engineering for Biotechnology of the Federal Research Centre of the Russian Academy of Sciences and author of the research.
“In this connection, there is a promising alternative to enzymes we now have — highly-stable asparaginases from micro-organisms found in extreme conditions. These proteins have demonstrated unique qualities.”
The asparaginases was found in the Samotlor oil field. The scientists accumulated proteins in the cells of intestinal bacteria, isolated them and tested their qualities in different conditions as well as their effects on cell cultures. As was demonstrated, it suppresses the growth of different types of cancerous cells, but at the same time has practically no effect on normal fibroblasts – the principal producers of the intercellular substance of tissue.
“Our results show that this asparaginases may serve as a good alternative to the enzymes we use now: it is active on a broad scale of temperatures and pH, resistant to metal ions and selectively toxic to tumours. That allows for its use at the very least in biochemistry,” said Alexander Zhgun, head of the group of fungal genetic engineering for Biotechnology of the Federal Research Centre of the Russian Academy of Sciences.
Scientists will now test asparaginases on animals – the results could indicate whether it can be used in medical practice.
