Supramolecular 3-d Metal 1,10-Phenanthroline Tartratostannates(IV) as Modifiers of α-L-Rhamnosidase Activity of Cryptococcus albidus, Eupenicillium erubescens and α-Galactosidase Activity of Penicillium restrictum

Abstract

In recent years, the particular interest of researchers is focused on such enzymes as α-L-rhamnosidase and α-galactosidase. These enzymes are considered useful for various applications. α-L-rhamnosidases may be applied for debittering of citrus fruit juices, due to the less bitter taste of the derhamnosylated flavonones, for rhamnose production, and for the determination of the anomeric configuration in polysaccharides, glycosides and glycolipids. These enzymes may enhance wine aroma and flavonoid bioavailability, or assist in the synthesis of pharmaceuticals. α-Galactosidase finds application in many areas. It is widely used in the food industry to improve the quality of soy products by hydrolyzing indigestible galactosides such as raffinose and stachyose, in the processing of raw materials in order to increase the yield of sugar from molasses, and for the biotransformation of human blood erythrocytes of group B (III) in universal donor erythrocytes, as well as in enzyme therapy of some congenital disorders of sphingolipid metabolism. Earlier, as a result of screening microorganisms of different taxonomic groups, we has selected active α-L-rhamnosidase and α-galactosidase producers. One way to increase their activity is using various effector compounds capable of modifying the enzyme activity. The study of the influence of various effectors is one of the priority areas of modern research in biochemistry, biocoordination chemistry, and biotechnology. Recent advantages in the area of biocoordination chemistry revealed high activating properties of double heterometallic mixed-ligand coor dination compounds with germanium(IV)/tin(IV) tartaric complex anions and 1,10-phenanthroline/2,2`-bipyridine d-metallic cations. The aim is to estimate the enzyme-effector activity of five similar tartratostannates for the α-L-rhamnosidases of Cryptococcus albidus, Eupenicillium erubescens, and α-galactosidase of Penicillium restrictum. Methods. The activity of α-Galactosidase was determined using p-nitrophenyl-α-D-galactopyranoside («Sigma», USA) as a substrate. The activity of α-L-rhamnosidase was determined using the Davis method. As modifiers of enzyme activity, [Fe(phen)3]2[Sn2(μ-Tart)2(Н2Tart)2]·2H2O (1), [Co(phen)3]2[Sn2(μ-Tart)2(Н2Tart)2]·8H2O (2), [Ni(phen)3]2[Sn2(μ-Tart)2(Н2Tart)2]·2H2O (3), [Cu(phen)3]2[Sn2(μ-Tart)2(Н2Tart)2]·2H2O (4), and [Zn(phen)3]2[Sn2(μ-Tart)2(Н2Tart)2]·6H2O (5) were used. Results. The study of the effect of complexes 1—5, which are supramolecular salts consisting of the same tartrate stannate anion (electrophilic agent) and a 1,10-phenanthroline d-metal cation (nucleophilic agent), on the Cryptococcus albidus, Eupenicillium erubescens α-L-rhamnosidases, and Penicillium restrictum α-galactosidase showed that the compounds tested had a different influence on the enzymes’ activity. The catalytic activity of α-L-rhamnosidase is significantly influenced by all complexes. The effectiveness of compounds 1—5 for P. restrictum α-galactosidase was less pronounced in comparison with C. albidus and E. erubescens α-L-rhamnosidases. It was mostly at the control level. There was observed a certain pattern in the influence of complexes on α-L-rhamnosidases of Cryptococcus albidus and Eupenicillium erubescens. Compounds 2 and 5 turned out to be the most effective and activated enzymes by 500-900%. Conclusions. Compound 2 [Co(phen)3]2[Sn2(μ-Tart)2(Н2Tart)2]·8H2O is promising for further use as an effector of the α-L-rhamnosidase activity.