A spectrophotometric assay for dissimilatory nitrite reductases

✍ Scribed by C.L. Hulse; J.M. Tiedje; B.A. Averill

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 560 KB
• Volume: 172
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(88)90464-2

✦ Synopsis

A spectrophotometric assay for dissimilatory nitrite reductases has been developed utilizing mammalian cytochrome c (equine heart) as reductant and spectrophotometric agent. The copper-containing nitrite reductase from Achromobacter cycloclastes has been shown to have apparent Km's for reduced cytochrome c and nitrite of 86 +/- 5 and 5.63 +/- 0.03 microM, respectively. The heme cd-containing enzyme from Pseudomonas stutzeri was shown to have apparent Km's for reduced cytochrome c and nitrite of 260 +/- 60 and 1.8 +/- 0.8 microM, respectively. This assay represents a simple, general method for consistently evaluating the activity of the copper- and heme cd-containing nitrite reductases that are capable of utilizing readily available mammalian cytochrome c as electron donor and should be useful for mechanistic studies of these enzymes.