[Stabilizing effect of calcium ions on glucose oxidase of Penicillium vitale]

Reconstruction of P. vitale glucose oxidase from apeonzyme and coenzyme (FAD) was studied as affected by iodine acetate as well as mercury and calcium ions. Mercury ions, iodine acetate as well as the labilizing fraction (flavin adenine-containing component) are established to inhibit the reconstruction affecting the sulphydryl groups of the apoenzyme which take part in addition of FAD to it. Calcium ions prevent the effect of the "labilizing" fraction, iodine acetate and mercury ions on the glucose oxidase apoenzyme as well as the effect of mercury ions on the glucose oxidase coenzyme. The effect of Ca2+ consists in "labilizing" fraction-calcium complexing.