Journalartikel
Autorenliste: SCHMITZ, RA; LINDER, D; STETTER, KO; THAUER, RK
Jahr der Veröffentlichung: 1991
Seiten: 427-434
Zeitschrift: Archives of Microbiology
Bandnummer: 156
Heftnummer: 5
ISSN: 0302-8933
DOI Link: https://doi.org/10.1007/BF00248722
Verlag: Springer
Abstract:
Methylene-H4MPT reductase was found to be present in Archaeoglobus fulgidus in a specific activity of 1 U/mg. The reductase was purified 410-fold. The native enzyme showed an apparent molecular mass of approximately 200 kDa. Sodium dodecylsulfate/polyacrylamide gel electrophoresis revealed the presence of only 1 polypeptide of apparent molecular mass 35 kDa. The ultraviolet/visible spectrum of the reductase was almost identical to that of albumin indicating the absence of a chromophoric prosthetic group. The reductase was dependent on reduced coenzyme F420 as electron donor. Neither NADH, NADPH, nor reduced viologen dyes could substitute for the reduced deazaflavin. From reciprocal plots, which showed an intersecting pattern, a K(m) for methylene-H4MPT of 16-mu-M, a K(m) for F420H2 of 4-mu-M, and a V(max) of 450 U/mg (k(cat) = 265 s-1) were obtained. The enzyme was found to be rapidly inactivated when incubated at 80-degrees-C in 100 mM Tris/HCl pH 7. The rate of inactivation, however, decreased to essentially zero in the presence of either F420 (0.2 mM), methylene-H4MPT (0.2 mM), albumin (1 mg/ml), or KCl (0.5 M). The N-terminal amino acid sequence was determined and found to be similar to that of methylene-H4MPT reductase (F420-dependent) from the methanogens Methanobacterium thermoautotrophicum, Methanosarcina barkeri, and Methanopyrus kandleri. The purification and some properties of formylmethanofuran dehydrogenase from A. fulgidus are also described.
Zitierstile
Harvard-Zitierstil: SCHMITZ, R., LINDER, D., STETTER, K. and THAUER, R. (1991) N5,N10-METHYLENETETRAHYDROMETHANOPTERIN REDUCTASE (COENZYME-F420-DEPENDENT) AND FORMYLMETHANOFURAN DEHYDROGENASE FROM THE HYPERTHERMOPHILE ARCHAEOGLOBUS-FULGIDUS, Archives of Microbiology, 156(5), pp. 427-434. https://doi.org/10.1007/BF00248722
APA-Zitierstil: SCHMITZ, R., LINDER, D., STETTER, K., & THAUER, R. (1991). N5,N10-METHYLENETETRAHYDROMETHANOPTERIN REDUCTASE (COENZYME-F420-DEPENDENT) AND FORMYLMETHANOFURAN DEHYDROGENASE FROM THE HYPERTHERMOPHILE ARCHAEOGLOBUS-FULGIDUS. Archives of Microbiology. 156(5), 427-434. https://doi.org/10.1007/BF00248722
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