Borate–fructose complex: A novel mediator for laccase and its new function for fructose determination

Abstract

a b s t r a c tLaccase and borate-fructose complex were investigated by coincidence in a solid-state fermentation of Edenia sp. TS-76 under fructose oxidase screening. Laccase was purified to homogeneity with a 34-fold purification and 32% yield. Fructose had no significant effect on laccase activity, whereas borate reduced laccase activity by 60-90%; conversely, the borate-fructose complex increased laccase activity by nearly fourfold at pH 7.5. The complex caused a shift in the optimal pH for laccase from 5.0 to 7.5 and served as a highly efficient mediator. Borate complexed with fructose provides an alternative, time-saving, and specific method for serum fructose determination.

Electron Transfer via Helical Oligopeptide to Laccase Including Chiral Schiff Base Copper Mediators

“…The better docking score of 2 may be due to hydrophobic interactions between the pocket and the azobenzene moiety (Figure 5) [22,31,32]. An ABTS essay measurement was performed to confirm the activity of the laccase/mediator complex (Figure 6) [36]. 0.1 mL laccase, laccase+1 or laccase+2 solutions (0.5 mg/mL) was mixed with a 2.9 mL ABTS solution (0.5 mM) fast, and the enzyme activity was examined by following the UVvis peak at 420 nm (peak of the oxidized ABTS) over time.…”

The Fructoborates: Part of a Family of Naturally Occurring Sugar–Borate Complexes—Biochemistry, Physiology, and Impact on Human Health: a Review

“…The outcome of these investigations could establish the connection between borate anion/sugar–borate anion/B and calcium related to certain genes’ regulation and expression. Additionally, the natural BCCs found in plants (glucose– as well as fructose–borates) have been predicted to be implicated within cell signaling systems of ROS [ 25 , 62 ]. Different clinical investigations have demonstrated the capacity of CaFB to regulate molecular markers of inflammation, mainly CRP [ 64 ].…”

“…Different clinical investigations have demonstrated the capacity of CaFB to regulate molecular markers of inflammation, mainly CRP [ 64 ]. Fructoborate has been recently found to be a powerful catalyst in various natural reactions in plants and perhaps it even acts as a coenzyme [ 62 ]. One study analyzed whether CaFB exerted antioxidant characteristics on cell cultures of human keratinocytes in order to determine whether CaFB could have potential application for use on skin wounds.…”

“…The fructoborate complex has been recently found to be a powerful catalyst in various biological reactions in plants, and it may act as a coenzyme (Fig. 4 ) [ 62 ].…”

“…Subsequently, fructoborate species may possess a biological role such as functioning as a coenzyme or cofactor (Fig. 3) [25, 62]. This is an intriguing concept that could be a scope of future investigations.

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