Obtaining peptides from aquatic organisms of the Antarctic region

The rapid growth in demand for peptide drugs is actualizing the search for new natural and economically viable sources of raw materials. Thewide variety of biologically active compounds, including peptide nature, inherent in marine aquatic organisms allows us to consider their promising raw material resource. However, the use of marine objects as a source for the production of target molecules requires some optimization of existing methodological approaches to their isolation and ensure the appropriate degree of purification. The problem of optimization of the method of obtaining peptides from hydrobionts of the Antarctic region on the example of the hydrobiont Nacellaconcinna is solved in the work. The proposed three-step approach allows to isolate fractions of peptides of different molecular weight. The first step involved the precipitation of high molecular weight protein material first with perchloric acid and then with 80% ethyl alcohol. The result was a fraction of peptide molecules with a molecular weight of up to 6.5 kDa, which contained a small amount of high molecular weight protein impurities. Further purification of the obtained fraction was performed by ultrafiltration using membranes with a pore size of 10 kDa. Control of the protein-peptide composition of the sample at all stages of production was performed by disk electrophoresis under denaturing conditions in plates of 18% polyacrylamide gel. Analysis using 2D electrophoresis found that the isoelectric points of most peptides are in the pH range from 8.0 to 10.0. Only a small proportion of the peptides had isoelectric points at 4.0 and 5.0 pH. The final step of obtaining the peptide fraction involved fractionation of the sample by gel chromatography. As a result of chromatographic separation, four peaks were obtained, corresponding to the fractions with peptides, the molecular weight of which is about 2.3 kDa (1 peak), 1.9 kDa (2 peak), 1.4 kDa (3 peak) and 0.7 kDa (4 peak).