Окисление фенола ковалентно иммобилизованной пероксидазой хрена

According to modified Bakh’s method, partially purified horseradish peroxidase preparation (RZ = 1,0; activity 100 U/mg of protein) was isolated. Molecular mass of obtained HPR (42 972 Da) was confirmed by massspectrometry: matrix activated laser desorption/ ionization. The enzyme was covalently immobilized by periodate oxidation of polysaccharide membrane «Diacell», followed by sodium borohydride reduction, at mass ratio enzyme: support 0.2:1. The biocatalyst with quantitative protein coupling, 88% of activity’s pH and thermooptima, increased termostability, stable at storage (8 months) was obtained. Kinetic studies had shown the increasing of hydrogen peroxide and pyrogallol K м values and decreasing of V max values during immobilized HPRcatalyzed reactions. In the batch reactor the biocatalyst developed promoted the quantitative phenol oxidation (1 mmol/dm 3) during 7 cycles of usage and high level of it’s bioconversion (95–50%) during the next 15 cycles. Molecular weight (about 2021 Da) of polymer product, insoluble in water and most organic solvent, of peroxidase oxidation of phenol — polioxyfenilene (particle size is from 15 to 75 mm) consisting of 21 units was first determined by laser desorption/ionization.