Dissimilatory sulfite reductase in cell-free extracts of intestinal sulfate-reducing bacteria
| Autor: | I. V. Kushkevych, R. V. Fafula |
|---|---|
| Jazyk: | English<br />Ukrainian |
| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Біологічні студії, Vol 8, Iss 2, Pp 101-112 (2014) |
| Druh dokumentu: | article |
| ISSN: | 1996-4536 2311-0783 |
| DOI: | 10.30970/sbi.0802.353 |
| Popis: | Dissimilatory sulfite reductase activity in different fractions of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 isolated from human intestine was studied. Sulfite reductase, an important enzyme in the process of sulfur metabolism in these bacteria, was solubilized from the membrane fraction. The highest activity of the enzyme in the cell-free extract of the bacterial strains was measured (0.032±0.0026 and 0.028±0.0022 U×mg-1 protein for D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively) compared to other fractions. The optimal temperature (+30…35 °C) and pH 7.0 for sulfite reductase reaction in the extracts of both bacterial strains was determined. The spectral analysis of purified sulfite reductase from cell-free extracts was carried out. The absorption maxima were 284, 391, 412, 583, and 630 nm, as well as 287, 393, 545, and 581 nm for sulfite reductase of D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively. Analysis of the kinetic properties of the bacterial sulfite reductase has been carried out. The sulfite reductase activity, initial (instantaneous) reaction rate (V0) and maximum rate of the sulfite reductase reaction (Vmax) were higher in the D. piger Vib-7 cells than in the Desulfomicrobium sp. Rod-9. However, Michaelis constants (Km) of the enzyme activity were similar for both bacterial strains. The studies of the sulfite reductase activity, the kinetic properties of this enzyme in the intestinal sulfate-reducing bacteria strains, and their production of hydrogen sulfide in detail can be useful for clarification of the etiological role of these bacteria in the development of inflammatory bowel diseases in humans and animals. |
| Databáze: | Directory of Open Access Journals |
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