Covalent immobilization of Candida methylica formate dehydrogenase on short spacer arm aldehyde group containing supports

In this study, three different aldehyde group containing supports, such as glyoxyl silica, glyoxyl agarose and aldehyde-functionalized Immobead 150 were evaluated for the covalent immobilization of formate dehydrogenase from Candida methylica. The immobilization−activity yields were determined as 75−68%, 60−84%, and 90−132%, respectively for glyoxyl silica, glyoxyl agarose and aldehyde-functionalized Immobead 150 supports for formate oxidation. The formate production activity of Candida methylica formate dehydrohenase was tested for different initial bicarbonate concentrations; however, no product was determined. The optimum pHs of free FDH and immobilized FDH on aldehyde-functionalized Immobead 150 were both 7.0, whereas the optimum pHs of the immobilized FDHs on glyoxyl silica and glyoxyl agarose were both 8.0. The optimum temperatures of all the FDH preparations were determined as 35°C. KM values of free FDH and immobilized FDH on glyoxyl silica, glyoxyl agarose and aldehyde-functionalized Immobead 150 supports were determined as 4.18±0.22, 3.06±0.14, 3.22±0.18, and 2.79±0.15mM, respectively for formate and 0.51±0.05, 0.49±0.02, 0.59±0.05, and 0.15±0.04mM, respectively for NAD+. The half-life time values of immobilized FDH on glyoxyl silica, glyoxyl agarose and aldehyde-functionalized Immobead 150 supports were 2.8, 3.1 and 3.6 times higher than that of the free FDH, respectively at 35°C. The immobilized FDH on glyoxyl silica, glyoxyl agarose and aldehyd...

Source: Journal of Molecular Catalysis B: Enzymatic - May 13, 2016 Category: Biochemistry Source Type: research