The possibility of using silochrome sorbents for proteinase inhibitor aprotinin

Background. Aprotinin is a polypeptide, a proteinase inhibitor of natural origin. It inhibits kallikrein, kininogenase, plasmin, trypsin, chymotrypsin; blocks the activator of profibrinolysin, which helps to stop bleeding. Aprotinin is obtained from the lungs of cattle. Objective. To study the sorption of aprotinin on silochromic sorbents. Materials and methods. Affinity sorbents based on silochrome were used in the work: p-chlorobenzyl-silochrome, active bright blue K-silochrome, aminopropyl silochrome, phenyl-diol-silochrome, phenyl-glutaryl-silochrome. The optical density was measured on KFK-3 (590 nm, 750 nm) and SF-46 (280 nm). An NP-3 peristaltic pump was used for chromatographic purification. Results and discussion. Based on the obtained data, it can be assumed that the mechanism of binding of aprotinin to all carriers is obviously the same and is based on the presence of hydrophobic sites in its molecule, which leads to hydrophobic interactions with sorbents. However, increasing the hydrophobicity of the eluent does not lead to desorption of the inhibitor. Obviously, in addition to hydrophobic, a significant role is played by the electrostatic interaction, which is eliminated by increasing the ionic strength. The sorbents under study have a high capacity, they do not change their volume when the ionic strength or hydrophobicity changes, and therefore may be suitable for large-scale applications. Conclusions. Affinity sorbents based on silochrome, containing as ligands aminobenzene, p-chlorobenzyl chloride and active chlorotriazine dye of the anthraquinone series “active bright blue K”, in contrast to the original matrix – silochrome aminopropyl water and effectively dissolve. Increasing the ionic strength or hydrophobicity of desorbing solutions does not lead to elution of aprotinin due to additional electrostatic interaction. Therefore, the desorption of aprotinin is achieved only if it is eliminated in the presence of 25 % isopropanol with 1M NaCl.