Characterisation of the components of the thioredoxin system in the archaeon Sulfolobus solfataricus(523 views) Grimaldi P, Ruocco MR, Lanzotti MA, Ruggiero A, Ruggiero I, Arcari P, Vitagliano L, Masullo M
Keywords: Active Site Disulfide, Archaea, Redox Potential, Sulfolobus Solfataricus, Thioredoxin System, Recombinant Protein, Thioredoxin Reductase, Article, Binding Site, Biochemistry, Biological Model, Catalysis, Genetics, Genome, Metabolism, Methodology, Oxidation Reduction Reaction, Physiology, Plasmid, Polyacrylamide Gel Electrophoresis, Oxidation-Reduction, Thioredoxin-Disulfide Reductase, Time Factors,
Affiliations: *** IBB - CNR ***
Dipartimento di Scienze Farmacobiologiche, Università di Catanzaro Magna Graecia, Complesso Ninì Barbieri, 88021 Roccelletta di Borgia, Catanzaro, Italy
Dipartimento di Biochimica e Biotecnologie Mediche, Università di Napoli Federico II, Via S. Pansini 5, 80131 Napoli, Italy
Istituto di Biostrutture e Bioimmagini, CNR, Via Mezzocannone 16, 80134 Napoli, Italy
Dipartimento Delle Scienze Biologiche, Sezione di Biostrutture, Università di Napoli Federico II, Via Mezzocannone 16, 80134 Napoli, Italy
CEINGE Biotecnologie Avanzate S.c.a R.l, Via Comunale Margherita 482, 80145 Napoli, Italy
References: Not available.
Characterisation of the components of the thioredoxin system in the archaeon Sulfolobus solfataricus
The thioredoxin system is a redox machinery widely distributed in nature and involved in several cellular functions. It is constituted of thioredoxin reductase (Trx-B), its protein substrate thioredoxin (Trx-A) and NADPH. We have previously characterised a Trx-B from the hyperthermophile Sulfolobus solfataricus (SsTrx-B3) (Ruocco et al. in Biochimie 86:883-892, 2004). As in the genome of this archaeon, the gene coding for another Trx-B (SsTrx-B2) and for two Trx-A (SsTrx-A1, SsTrx-A2) have been putatively identified, these proteins were obtained as recombinant forms and characterised. SsTrx-B2, different from SsTrx-B3, did not elicit a thioredoxin reductase activity. S. solfataricus possessed only one Trx-B (SsTrx-B3), which had two thioredoxins (SsTrx-A1 and SsTrx-A2) as substrates. These latter showed a homodimeric structure and catalysed insulin reduction using either DTT or NADPH/SsTrx-B3 as electron donors. In addition, the electron transfer between SsTrx-B3 and either SsTrx-A1 or SsTrx-A2 was fully reversible, thus allowing the determination of the redox potential of the thioredoxin system in S. solfataricus. Among the two thioredoxins, SsTrx-A2 appeared slightly more active and stable than SsTrx-A1. These data, besides shedding light on thioredoxin system in S. solfataricus, will contribute to add further information on this key enzyme system in Archaea.
Characterisation of the components of the thioredoxin system in the archaeon Sulfolobus solfataricus