Reactivative Action of Ethylenediaminetetraacetic Acid or Dipicolinic Acid on Inactive Glucose Dehydrogenase Obtained from Heated Spores of Bacillus subtilis

Abstract

Partially purified inactive glucose dehydrogenase obtained from spores which were heated at 87 or 90 C for 30 min is converted to an active form by the addition of ethylenediaminetetraacetic acid, dipicolinic acid, or some salts. The molecular weight of the inactive glucose dehydrogenase in the heated spores is about one-half of that of the active glucose dehydrogenase in the intact resting spores. The possibility is discussed that the active glucose dehydrogenase in the intact resting spores divides into subunits and is converted to stable and inactive form during heating of spores at a particular range of temperature (87 to 90 C).

Effect of Disruption by Sonication under Different Conditions on the Activity of Glucose Dehydrogenase from Resting Spores of Bacillus subtilis

“…When resting spores suspended in 100 mM phosphate buffer in the range of pH 6.0 to 6.6 were sonicated for 30 min at 1.45 A by using a Kubota Insonator, their soluble fraction contained glucose dehydrogenase showing considerably high specific activity, with a value constantly between 800 and 1,100 nmol of NAD or NADP reduced per min per mg of protein (Tables 2, 3, 6). As the conditions for preparation of spore extracts used by us are not necessarily identical to those used by other researchers, it is difficult to compare strictly our data with theirs, but it seems legitimate to consider that the values of specific activity of glucose dehydrogenase which we show here are generally much higher than those reported so far for B. subtilis and B. megaterium (6,13,15).…”

“…Our laboratory has reported that EDTA.4Na and various salts such as NaCI, KCI, and LiCI convert inactive glucose dehydrogenase from heated spores of B. subtilis to the active form (6). A series of experiments was performed, with this phenomenon as a clue.…”

α-α′-Dipyridyl or Ortho -Phenanthroline Stimulation of the Soluble Reduced Nicotinamide Adenine Dinucleotide Oxidase from Bacillus subtilis Spores and Dipicolinic Acid Inhibition of the Stimulated Enzyme

“…DPA has usually been suspected to be important in the maintenance of heat resistance (2). Hachisuka et al have suggested that DPA stabilizes the heatlabile glucose dehydrogenase from B. subtilis spores (6), and the inactive glucose dehydrogenase obtained from heated spores changes to an active form by DPA (5). Halvorson et al (7) found that DPA stimulated NADH cytochrome c reductase and diaphorase of spores and vegetative cells of B. cereus T, and Doi and Halvorson (4) demonstrated that it also stimulated the soluble NADH oxidase of spores.…”