## 4 Discussion
Thus, the effect observed in our experiments cannot be attributed to the action of a transverse electromagnetic radiation, which could take place if the coil was not ground-shielded. The phenomena revealed in our experiments can be explained by the formation of a longitudinal field by the flow of glycerol. The effect of such a field, intentionally formed by means of a specialized generator, on the enzyme was observed for the first time by [PERSON] et al. [28]. It was noted that such electromagnetic fields, which have a specific topology [67; 68; 69; 70], can influence biological objects (including enzymes) at even very low power densities, comparable with the background radiation level [22]. The effect of the field on both the enzyme aggregation and its enzymatic activity can be explained by the change in the structure of the enzyme's hydration shell under the action of the field. Indeed, the structure of the hydration shell was shown to be one of the factors influencing the functioning of biological macromolecules [71]. And in the case of enzymes, their enzymatic activity can be well-affected by alterations in their hydration shells [71; 72; 73], and this is what we have observed in our experiments with HRP enzyme. This is how we explain the effect of glycerol flow on HRP enzyme in our particular case. HRP is known to readily form aggregates, particularly at micromolar concentrations [74]. Considering the temperature range from 15 to 40 \({}^{\circ}\)C, the content of aggregates in the case of the adsorption of HRP on mica was found to be slightly higher at room temperature and pH 7.4 [75]. Here, it should be emphasized that the aggregation of an enzyme does not imply the loss of its activity. Although aggregated enzymes are often considered as less active than non-aggregated ones [76], the existence of a correlation between the enzyme aggregation and enzymatic activity depends on the enzyme type. According to [PERSON] et al., no aggregation-induced attenuation of catalytic activity was revealed for hexokinase and alkaline phosphatase [77]. And in our experiments, we have observed an increase in the aggregation of HRP on mica accompanied by a 20% increase in its activity against ABTS. The structural stability of HRP is known to be dependent on such important factors as temperature and pH [78]. The highest temperature stability of this enzyme was observed at pH > 6.5. In order to avoid an interference of the pH on the enzyme structure, prior to the incubation in the experimental setup, we had dissolved the enzyme in PBSD buffer with pH 7.4. Generally, both the high temperature and the acidic pH are known to be the factors inducing protein denaturation--that is, the partial or complete disarrangement of its spatial structure. The considerable unfolding of HRP tertiary and secondary structures was observed at acidic pH < 4.5 [78]. It is to be noted that pH directly influences the electrostatic mechanism of enzyme adsorption [79]. In general, enzyme adsorption represents a complex process, which involves the interactions of enzyme macromolecules with each other (that is, enzyme aggregation), with the surface and with the solvent [80]. Based on these considerations, we have conducted our experiments at room temperature and pH 7.4 in order to confirm that the observed effects on the enzyme aggregation and activity are only caused by the field generated in the experimental setup. The enzyme may behave differently upon a change in either the pH, the ionic strength or the temperature [79], and this should be studied in the future.