Polymeric particles formed by stearoyl-poly-N-vinylpyrrolidone (PVP-stear) of M(n) = 2600 were obtained in aqueous solution, and their shape and size distribution were characterized. The size of the particles was shown to decrease with an increase in the ionic strength of the solution. Interaction of PVP-stear and its aggregates with model proteins (Bowman-Birk soybean proteinase inhibitor (BBI) and its hydrophobized derivatives) was studied. The possibility of inclusion of both native BBI and oleoylic derivative of BBI in the PVP-stear polymeric aggregates was investigated. It was established that polymeric particles with a diameter of 30 nm formed under certain concentration ratios between PVP-stear and poorly soluble dioleoyl BBI are capable of solubilization of dioleoyl BBI as well as prevention of its inactivation at low pH values.

The effect of acylation of Bowman-Birk soybean proteinase inhibitor (BBI) by derivatives of various unsaturated fatty acids on inhibition of trypsin, alpha-chymotrypsin, and human leukocyte elastase was investigated. Inhibition (K(i)) and kinetic (k(ass), k(diss)) constants of interaction between proteases and acylated BBI derivatives were determined. For mono-, di-, and triacylated BBI derivatives, insertion of two oleic residues into the BBI molecule was demonstrated to be more potent for exhibiting antiproteinase activity.

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A procedure was developed for acylation of Bowman-Birk soybean proteinase inhibitor (BBI) by N-hydroxysuccinimide esters of oleic, linoleic, and alpha-linolenic acids in a dimethyl sulfoxide-dioxane-pyridine mixture. BBI derivatives containing two acylated amino groups were prepared with high yield. The use of the reversible modifier citraconic anhydride in the first stage of synthesis permitted the synthesis of hydrophobized BBI derivatives retaining high antitrypsin and antichymotrypsin activities. It was found that the insertion of two long-chain moieties in the BBI molecule decreases its thermostability.