[{"page":"4 - 12","issue":"1","publication":"Biochimica et Biophysica Acta - Bioenergetics","type":"journal_article","day":"11","status":"public","intvolume":"      1273","date_created":"2018-12-11T11:54:53Z","date_published":"1996-01-11T00:00:00Z","article_type":"original","month":"01","language":[{"iso":"eng"}],"publisher":"Elsevier","volume":1273,"date_updated":"2022-08-16T12:35:22Z","publist_id":"5132","article_processing_charge":"No","acknowledgement":"L.A.S. would like to thank the Wellcome Trust, and T.B., the Biotechnology and Biological Sciences Research Council, for financial support. We are very grateful to Nick Cotton for helpful advice.","user_id":"ea97e931-d5af-11eb-85d4-e6957dddbf17","oa_version":"None","quality_controlled":"1","pmid":1,"_id":"1952","extern":"1","publication_identifier":{"issn":["0005-2728"]},"publication_status":"published","citation":{"ista":"Bizouarn T, Sazanov LA, Aubourg S, Jackson J. 1996. Estimation of the H+/H- ratio of the reaction catalysed by the nicotinamide nucleotide transhydrogenase in chromatophores from over-expressing strains of Rhodospirillum rubrum and in liposomes inlaid with the purified bovine enzyme. Biochimica et Biophysica Acta - Bioenergetics. 1273(1), 4–12.","short":"T. Bizouarn, L.A. Sazanov, S. Aubourg, J. Jackson, Biochimica et Biophysica Acta - Bioenergetics 1273 (1996) 4–12.","mla":"Bizouarn, Tania, et al. “Estimation of the H+/H- Ratio of the Reaction Catalysed by the Nicotinamide Nucleotide Transhydrogenase in Chromatophores from over-Expressing Strains of Rhodospirillum Rubrum and in Liposomes Inlaid with the Purified Bovine Enzyme.” <i>Biochimica et Biophysica Acta - Bioenergetics</i>, vol. 1273, no. 1, Elsevier, 1996, pp. 4–12, doi:<a href=\"https://doi.org/10.1016/0005-2728(95)00125-5\">10.1016/0005-2728(95)00125-5</a>.","ama":"Bizouarn T, Sazanov LA, Aubourg S, Jackson J. Estimation of the H+/H- ratio of the reaction catalysed by the nicotinamide nucleotide transhydrogenase in chromatophores from over-expressing strains of Rhodospirillum rubrum and in liposomes inlaid with the purified bovine enzyme. <i>Biochimica et Biophysica Acta - Bioenergetics</i>. 1996;1273(1):4-12. doi:<a href=\"https://doi.org/10.1016/0005-2728(95)00125-5\">10.1016/0005-2728(95)00125-5</a>","chicago":"Bizouarn, Tania, Leonid A Sazanov, Sébastien Aubourg, and Julie Jackson. “Estimation of the H+/H- Ratio of the Reaction Catalysed by the Nicotinamide Nucleotide Transhydrogenase in Chromatophores from over-Expressing Strains of Rhodospirillum Rubrum and in Liposomes Inlaid with the Purified Bovine Enzyme.” <i>Biochimica et Biophysica Acta - Bioenergetics</i>. Elsevier, 1996. <a href=\"https://doi.org/10.1016/0005-2728(95)00125-5\">https://doi.org/10.1016/0005-2728(95)00125-5</a>.","ieee":"T. Bizouarn, L. A. Sazanov, S. Aubourg, and J. Jackson, “Estimation of the H+/H- ratio of the reaction catalysed by the nicotinamide nucleotide transhydrogenase in chromatophores from over-expressing strains of Rhodospirillum rubrum and in liposomes inlaid with the purified bovine enzyme,” <i>Biochimica et Biophysica Acta - Bioenergetics</i>, vol. 1273, no. 1. Elsevier, pp. 4–12, 1996.","apa":"Bizouarn, T., Sazanov, L. A., Aubourg, S., &#38; Jackson, J. (1996). Estimation of the H+/H- ratio of the reaction catalysed by the nicotinamide nucleotide transhydrogenase in chromatophores from over-expressing strains of Rhodospirillum rubrum and in liposomes inlaid with the purified bovine enzyme. <i>Biochimica et Biophysica Acta - Bioenergetics</i>. Elsevier. <a href=\"https://doi.org/10.1016/0005-2728(95)00125-5\">https://doi.org/10.1016/0005-2728(95)00125-5</a>"},"author":[{"first_name":"Tania","last_name":"Bizouarn","full_name":"Bizouarn, Tania"},{"id":"338D39FE-F248-11E8-B48F-1D18A9856A87","first_name":"Leonid A","last_name":"Sazanov","full_name":"Sazanov, Leonid A","orcid":"0000-0002-0977-7989"},{"first_name":"Sébastien","last_name":"Aubourg","full_name":"Aubourg, Sébastien"},{"first_name":"Julie","last_name":"Jackson","full_name":"Jackson, Julie"}],"abstract":[{"lang":"eng","text":"Two strains of Rhodospirillum rubrum were constructed in which, by a gene dosage effect, the transhydrogenase activity of isolated chromatophores was increased 7-10-fold and 15-20-fold, respectively. The H+/H- ratio (the ratio of protons translocated per hydride ion equivalent transferred from NADPH to an NAD+ analogue, acetyl pyridine adenine dinucleotide), determined by a spectroscopic technique, was approximately 1.0 for chromatophores from the over-expressing strains, but was only approximately 0.6 for wild-type chromatophores. Highly-coupled proteoliposomes were prepared containing purified transhydrogenase from beef-heart mitochondria. Using the same technique, the H+/H- ratio was close to 1.0 for these proteoliposomes. It is suggested that the mechanistic H+/H- ratio is indeed unity, but that a low ratio is obtained in wild-type chromatophores because of inhomogeneity in the vesicle population."}],"year":"1996","doi":"10.1016/0005-2728(95)00125-5","external_id":{"pmid":["8573594 "]},"title":"Estimation of the H+/H- ratio of the reaction catalysed by the nicotinamide nucleotide transhydrogenase in chromatophores from over-expressing strains of Rhodospirillum rubrum and in liposomes inlaid with the purified bovine enzyme"},{"doi":"10.1016/0005-2728(95)00096-2","year":"1995","external_id":{"pmid":["7578218"]},"title":"Cyclic reactions catalysed by detergent-dispersed and reconstituted transhydrogenase from beef heart mitochondria; implications for the mechanism of proton translocation","main_file_link":[{"open_access":"1","url":"https://www.sciencedirect.com/science/article/pii/0005272895000962?via%3Dihub"}],"citation":{"chicago":"Sazanov, Leonid A, and Baz Jackson. “Cyclic Reactions Catalysed by Detergent-Dispersed and Reconstituted Transhydrogenase from Beef Heart Mitochondria; Implications for the Mechanism of Proton Translocation.” <i>Biochimica et Biophysica Acta - Bioenergetics</i>. Elsevier, 1995. <a href=\"https://doi.org/10.1016/0005-2728(95)00096-2\">https://doi.org/10.1016/0005-2728(95)00096-2</a>.","apa":"Sazanov, L. A., &#38; Jackson, B. (1995). Cyclic reactions catalysed by detergent-dispersed and reconstituted transhydrogenase from beef heart mitochondria; implications for the mechanism of proton translocation. <i>Biochimica et Biophysica Acta - Bioenergetics</i>. Elsevier. <a href=\"https://doi.org/10.1016/0005-2728(95)00096-2\">https://doi.org/10.1016/0005-2728(95)00096-2</a>","ieee":"L. A. Sazanov and B. Jackson, “Cyclic reactions catalysed by detergent-dispersed and reconstituted transhydrogenase from beef heart mitochondria; implications for the mechanism of proton translocation,” <i>Biochimica et Biophysica Acta - Bioenergetics</i>, vol. 1231, no. 3. Elsevier, pp. 304–312, 1995.","short":"L.A. Sazanov, B. Jackson, Biochimica et Biophysica Acta - Bioenergetics 1231 (1995) 304–312.","ista":"Sazanov LA, Jackson B. 1995. Cyclic reactions catalysed by detergent-dispersed and reconstituted transhydrogenase from beef heart mitochondria; implications for the mechanism of proton translocation. Biochimica et Biophysica Acta - Bioenergetics. 1231(3), 304–312.","mla":"Sazanov, Leonid A., and Baz Jackson. “Cyclic Reactions Catalysed by Detergent-Dispersed and Reconstituted Transhydrogenase from Beef Heart Mitochondria; Implications for the Mechanism of Proton Translocation.” <i>Biochimica et Biophysica Acta - Bioenergetics</i>, vol. 1231, no. 3, Elsevier, 1995, pp. 304–12, doi:<a href=\"https://doi.org/10.1016/0005-2728(95)00096-2\">10.1016/0005-2728(95)00096-2</a>.","ama":"Sazanov LA, Jackson B. Cyclic reactions catalysed by detergent-dispersed and reconstituted transhydrogenase from beef heart mitochondria; implications for the mechanism of proton translocation. <i>Biochimica et Biophysica Acta - Bioenergetics</i>. 1995;1231(3):304-312. doi:<a href=\"https://doi.org/10.1016/0005-2728(95)00096-2\">10.1016/0005-2728(95)00096-2</a>"},"publication_status":"published","abstract":[{"lang":"eng","text":"Transhydrogenase from beef-heart mitochondria was solubilised with Triton X-100 and purified by column chromatography. The detergent-dispersed enzyme catalysed the reduction of acetylpyridine adenine dinucleotide (AcPdAD+) by NADH, but only in the presence of NADP+. Experiments showed that this reaction was cyclic; NADP(H), whilst remaining bound to the enzyme, was alternately reduced by NADH and oxidised by AcPdAD+. A period of incubation of the enzyme with NADPH at pH 6.0 led to inhibition of the simple transhydrogenation reaction between AcPdAD+ and NADPH. However, after such treatment, transhydrogenase acquired the ability to catalyse the (NADPH-dependent) reduction of AcPdAD+ by NADH. It is suggested that this is a similar cycle to the one described above. Evidently, the binding affinity for NADP+ increases as a consequence of the inhibition process resulting from prolonged incubation with NADPH. The pH dependences of simple and cyclic transhydrogenation reactions are described. Though more complex than those in Escherichia coli transhydrogenase, they are consistent with the view [Hutton, M., Day, J.M., Bizouarn, T. and Jackson, J.B. (1994) Eur. J. Biochem. 219, 1041–10511] that, also in the mitochondrial enzyme, binding the release of NADP+ and NADP are accompanied by binding and release of a proton. The enzyme was successfully reconstituted into liposomes by a cholate dilution procedure. The proteoliposomes catalysed cyclic NADPH-dependent reduction of AcPdAD+ by NADH only when they were tightly coupled. However, they catalysed cyclic NADP+-dependent reduction of AcPdAD+ by NADH only when they were uncoupled eg. by addition of carbonylcyanide-p-trifluoromethoxyphenyl hydrazone. These observations are evidence that the proton binding and release which accompany NADP+ binding and release, respectively, take place on the inside of the vesicle, and that they are components of the electrogenic processes of the enzyme."}],"author":[{"id":"338D39FE-F248-11E8-B48F-1D18A9856A87","first_name":"Leonid A","full_name":"Sazanov, Leonid A","last_name":"Sazanov","orcid":"0000-0002-0977-7989"},{"first_name":"Baz","full_name":"Jackson, Baz","last_name":"Jackson"}],"article_processing_charge":"No","date_updated":"2022-06-29T15:04:47Z","volume":1231,"publist_id":"5142","oa":1,"publication_identifier":{"issn":["0005-2728"]},"extern":"1","pmid":1,"_id":"1943","oa_version":"Published Version","quality_controlled":"1","acknowledgement":"L.A.S. is grateful to the Wellcome Trust for a Research Fellowship. Support from the Biotechnology and Biological Sciences Research Council is also acknowledged. We thank our colleagues. Tania Bizouarn, Mike Hutton and Nick Cotton, for advice and valuable discussion. ","user_id":"ea97e931-d5af-11eb-85d4-e6957dddbf17","month":"10","date_published":"1995-10-10T00:00:00Z","article_type":"original","publisher":"Elsevier","language":[{"iso":"eng"}],"date_created":"2018-12-11T11:54:50Z","day":"10","type":"journal_article","intvolume":"      1231","status":"public","publication":"Biochimica et Biophysica Acta - Bioenergetics","issue":"3","page":"304 - 312"},{"language":[{"iso":"eng"}],"scopus_import":"1","publisher":"Elsevier","date_published":"1993-09-13T00:00:00Z","article_type":"original","month":"09","date_created":"2018-12-11T11:54:52Z","status":"public","intvolume":"      1144","type":"journal_article","day":"13","page":"225 - 228","publication":"Biochimica et Biophysica Acta - Bioenergetics","issue":"2","title":"Activation and inhibition of mitochondrial transhydrogenase by metal ions","external_id":{"pmid":["8369341 "]},"year":"1993","doi":"10.1016/0005-2728(93)90177-H","main_file_link":[{"url":"https://www.sciencedirect.com/science/article/pii/000527289390177H?via%3Dihub"}],"author":[{"orcid":"0000-0002-0977-7989","full_name":"Sazanov, Leonid A","last_name":"Sazanov","first_name":"Leonid A","id":"338D39FE-F248-11E8-B48F-1D18A9856A87"},{"first_name":"Julie","last_name":"Jackson","full_name":"Jackson, Julie"}],"abstract":[{"text":"Mitochondrial transhydrogenase has been reported previously to be inhibited by high, rather non-physiological concentrations (in the range of 2-20 mM) of divalent cations. We show that the enzyme could be activated by low (from about 1 μM to 1 mM) concentrations of Ca2+ and Mg2+, which are within physiological range. These results bring in line the effects observed with mitochondrial enzyme to the findings with bacterial transhydrogenases. The activation of transhydrogenase by divalent cations is interpreted as an increase in affinity of the NADP(H)-binding site of the enzyme-NAD(H) complex. Reported effects of the metal ions could be important for the enzyme function in vivo.","lang":"eng"}],"citation":{"short":"L.A. Sazanov, J. Jackson, Biochimica et Biophysica Acta - Bioenergetics 1144 (1993) 225–228.","ista":"Sazanov LA, Jackson J. 1993. Activation and inhibition of mitochondrial transhydrogenase by metal ions. Biochimica et Biophysica Acta - Bioenergetics. 1144(2), 225–228.","ama":"Sazanov LA, Jackson J. Activation and inhibition of mitochondrial transhydrogenase by metal ions. <i>Biochimica et Biophysica Acta - Bioenergetics</i>. 1993;1144(2):225-228. doi:<a href=\"https://doi.org/10.1016/0005-2728(93)90177-H\">10.1016/0005-2728(93)90177-H</a>","mla":"Sazanov, Leonid A., and Julie Jackson. “Activation and Inhibition of Mitochondrial Transhydrogenase by Metal Ions.” <i>Biochimica et Biophysica Acta - Bioenergetics</i>, vol. 1144, no. 2, Elsevier, 1993, pp. 225–28, doi:<a href=\"https://doi.org/10.1016/0005-2728(93)90177-H\">10.1016/0005-2728(93)90177-H</a>.","chicago":"Sazanov, Leonid A, and Julie Jackson. “Activation and Inhibition of Mitochondrial Transhydrogenase by Metal Ions.” <i>Biochimica et Biophysica Acta - Bioenergetics</i>. Elsevier, 1993. <a href=\"https://doi.org/10.1016/0005-2728(93)90177-H\">https://doi.org/10.1016/0005-2728(93)90177-H</a>.","apa":"Sazanov, L. A., &#38; Jackson, J. (1993). Activation and inhibition of mitochondrial transhydrogenase by metal ions. <i>Biochimica et Biophysica Acta - Bioenergetics</i>. Elsevier. <a href=\"https://doi.org/10.1016/0005-2728(93)90177-H\">https://doi.org/10.1016/0005-2728(93)90177-H</a>","ieee":"L. A. Sazanov and J. Jackson, “Activation and inhibition of mitochondrial transhydrogenase by metal ions,” <i>Biochimica et Biophysica Acta - Bioenergetics</i>, vol. 1144, no. 2. Elsevier, pp. 225–228, 1993."},"publication_status":"published","oa_version":"None","quality_controlled":"1","user_id":"ea97e931-d5af-11eb-85d4-e6957dddbf17","acknowledgement":"This work was supported by a Wellcome Trust fellowship to L.A.S. ","publication_identifier":{"issn":["0005-2728"]},"extern":"1","pmid":1,"_id":"1947","article_processing_charge":"No","volume":1144,"date_updated":"2022-06-01T12:51:32Z","publist_id":"5136"}]