Soluble reduced nicotinamide adenine dinucleotide oxidase from Bacillus cereus T spores and vegetative cells. II. Properties

Abstract

Two soluble reduced nicotinamide adenine dinucleotide (NADH2) oxidases purified from extracts of Bacillus cereus T spores were compared with vegetative ceil soluble NADH2 oxidase. The minor spore component and vegetative cell soluble NADH2 oxidase reacted equally well with riboflavin or flavin mononucleotide (FMN), were inhibited by 15 mM dipicolinic acid (DPA), and possessed similar thermal inactivation characteristics at 80 °C. Activity of the major spore component was stimulated by a factor of 3.6 when riboflavin replaced FMN as the coenzyme. The major spore component was not inhibited by DPA and resisted heat treatments which inactivated vegetative cell soluble NADH2 oxidase. These observations indicate that the minor spore component and vegetative cell soluble NADH2 oxidase are identical while the major spore component is a distinct protein.