Purification and characterization of glucose dehydrogenase from the thermoacidophilic archaebacterium Thermoplasma acidophilum

Abstract

Glucose dehydrogenase was purified to homogeneity from the thermoacidophilic archaebacterium Thermoplasma acidophilum. The enzyme is a tetramer of polypeptide chain Mr 38,000 +/- 3000, it is catalytically active with both NAD+ and NADP+ cofactors, and it is thermostable and remarkably resistant to a variety of organic solvents. The amino acid composition was determined and compared with those of the glucose dehydrogenases from the archaebacterium Sulfolobus solfataricus and the eubacteria Bacillus subtilis and Bacillus megaterium. The N-terminal amino acid sequence of the Thermoplasma acidophilum enzyme was determined to be: (S/T)-E-Q-K-A-I-V-T-D-A-P-K-G-G-V-K-Y-T-T-I-D-M-P-E.

Glucose dehydrogenase from the halophilic Archaeon Haloferax mediterranei: Enzyme purification, characterisation and N‐terminal sequence

“…The catalytic properties of the purified halophilic glucose dehydrogenase were similar to those reported for the enzyme from other Archaea, such as T. acidophilum [6,19], S. solfataricus [7], Thermoproteus tenax [20]. H. mediterranei glucose dehydrogenase is catalytically active with both coenzymes NAD + and NADP +.…”

“…G ucose + NAD(P) + ~ gluconate + NAD(P)H + H + Giucose dehydrogenases from the thermophilic Archaea, TJ ermoplasrna acidophilum [6] and Sulfolobus solfataricus [7], ar~" also dual-cofactor specific, and are able to oxidise a numbee of sugars. The gene encoding the T. acidophilum glucose dehydrogenase has been cloned, sequenced and over-expressed in E. coli [8], and the 3D structure of the recombinant enzyme ha s been determined [9].…”

Analysis of Bacterial Glucose Dehydrogenase Homologs from Thermoacidophilic ArchaeonThermoplasma acidophilum: Finding and Characterization of Aldohexose Dehydrogenase

“…The purified enzyme from thermoacidophilic archaeon Thermoplasma acidophilum (Ta-GDH) has been characterized. 6) Ta-GDH, consist of 352 amino acid residues, exhibited a much larger molecular weight of subunit than the bacterial NAD(P) þ -dependent glucose dehydrogenases. The deduced amino acid sequence of Ta-GDH showed less than 20% identity with those of Bacillus species.…”

Characterization of a thermostable glucose dehydrogenase with strict substrate specificity from a hyperthermophilic archaeon Thermoproteus sp. GDH-1

“…14) According to previous reports, other archaeal GDHs, such as SsGDH, TaGDH, PtGDH, TvGDH, and HmGDH, also preferred NADP + to NAD + . 13,[15][16][17]22) It, therefore, seems that archaeal GDHs commonly prefer NADP + as cofactor.…”

“…It is, therefore, not surprising that several NAD(P)-dependent GDHs from hyperthermophilic archaea have been characterized. In some hyperthermophilic archaea, such as Sulfolobus solfataricus 13) and Thermoproteus tenax, 14) or the thermoacidophilic archaeon Thermoplasma acidophilum, 15) Picrophilus torridus, 16) and Thermoplasma volcanium, 17) NAD(P)-GDH represents the first enzyme in the modified Entner-Doudoroff pathway. 18) Although these enzymes displayed high levels of (thermo)stability, most of the enzymes characterized thus far have exhibited relatively broad substrate specificity compared to their bacterial counterparts such as those from Bacillus subtilis 19) and Bacillus megaterium.…”