Endre søk
Link to record
Permanent link

Direct link
BETA
Publikasjoner (10 av 29) Visa alla publikasjoner
Enmark, M., Rova, M., Samuelsson, J., Örnskov, E., Schweikart, F. & Fornstedt, T. (2019). Investigation of factors influencing the separation of diastereomers of phosphorothioated oligonucleotides. Analytical and Bioanalytical Chemistry, 411(15), 3383-3394
Åpne denne publikasjonen i ny fane eller vindu >>Investigation of factors influencing the separation of diastereomers of phosphorothioated oligonucleotides
Vise andre…
2019 (engelsk)Inngår i: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 411, nr 15, s. 3383-3394Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

This study presents a systematic investigation of factors influencing the chromatographic separation of diastereomers of phosphorothioated pentameric oligonucleotides as model solutes. Separation was carried out under ion-pairing conditions using an XBridge C18 column. For oligonucleotides with a single sulfur substitution, the diastereomer selectivity was found to increase with decreasing carbon chain length of the tertiary alkylamine used as an ion-pair reagent. Using an ion-pair reagent with high selectivity for diastereomers, triethylammonium, it was found the selectivity increased with decreased ion-pair concentration and shallower gradient slope. Selectivity was also demonstrated to be dependent on the position of the modified linkage. Substitutions at the center of the pentamer resulted in higher diastereomer selectivity compared to substitutions at either end. For mono-substituted oligonucleotides, the retention order and stereo configuration were consistently found to be correlated, with Rp followed by Sp, regardless of which linkage was modified. The type of nucleobase greatly affects the observed selectivity. A pentamer of cytosine has about twice the diastereomer selectivity of that of thymine. When investigating the retention of various oligonucleotides eluted using tributylammonium as the ion-pairing reagent, no diastereomer selectivity could be observed. However, retention was found to be dependent on both the degree and position of sulfur substitution as well as on the nucleobase. When analyzing fractions collected in the front and tail of overloaded injections, a significant difference was found in the ratio between Rp and Sp diastereomers, indicating that the peak broadening observed when using tributylammonium could be explained by partial diastereomer separation.

sted, utgiver, år, opplag, sider
Springer, 2019
Emneord
IP-RPLC, Ion-pair, Oligonucleotide, Antisense, Phosphorothioate, Diastereomerr
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:kau:diva-72453 (URN)10.1007/s00216-019-01813-2 (DOI)000469757300016 ()
Tilgjengelig fra: 2019-06-12 Laget: 2019-06-12 Sist oppdatert: 2020-01-15
Hellberg Lindqvist, M., Nilsson, T., Sundin, P. & Rova, M. (2015). Chlorate reductase is cotranscribed with cytochrome c and other downstream genes in the gene cluster for chlorate respiration of Ideonella dechloratans. FEMS Microbiology Letters, 362(6)
Åpne denne publikasjonen i ny fane eller vindu >>Chlorate reductase is cotranscribed with cytochrome c and other downstream genes in the gene cluster for chlorate respiration of Ideonella dechloratans
2015 (engelsk)Inngår i: FEMS Microbiology Letters, ISSN 0378-1097, E-ISSN 1574-6968, Vol. 362, nr 6Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The chlorate-respiring bacterium Ideonella dechloratans is a facultative anaerobe that can use both oxygen and chlorate as terminal electron acceptors. The genes for the enzymes chlorate reductase (clrABDC) and chlorite dismutase, necessary for chlorate metabolism and probably acquired by lateral gene transfer, are located in a gene cluster that also includes other genes potentially important for chlorate metabolism. Among those are a gene for cytochrome c (cyc) whose gene product may serve as an electron carrier during chlorate reduction, a cofactor biosynthesis gene (mobB) and a predicted transcriptional regulator (arsR). Only chlorate reductase and chlorite dismutase have been shown to be expressed in vivo. Here, we report the in vivo production of a single polycistronic transcript covering eight open reading frames including clrABDC, cyc, mobB and arsR. Transcription levels of the cyc and clrA genes were compared to each other by the use of qRT-PCR in RNA preparations from cells grown under aerobic or chlorate reducing anaerobic conditions. The two genes showed the same mRNA levels under both growth regimes, indicating that no transcription termination occurs between them. Higher transcription levels were observed at growth without external oxygen supply. Implications for electron pathway integration following lateral gene transfer are discussed.

Emneord
anaerobic respiration; gene expression; oxochlorates
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:kau:diva-40700 (URN)10.1093/femsle/fnv019 (DOI)000356885900007 ()
Tilgjengelig fra: 2016-02-25 Laget: 2016-02-25 Sist oppdatert: 2017-12-06bibliografisk kontrollert
Nilsson, T., Rova, M. & Smedja Bäcklund, A. (2013). Microbial metabolism of oxochlorates: A bioenergetic perspective. Biochimica et Biophysica Acta - Bioenergetics, 1827(2), 189-197
Åpne denne publikasjonen i ny fane eller vindu >>Microbial metabolism of oxochlorates: A bioenergetic perspective
2013 (engelsk)Inngår i: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1827, nr 2, s. 189-197Artikkel, forskningsoversikt (Fagfellevurdert) Published
Abstract [en]

The microbial metabolism of oxochlorates is part of the biogeochemical cycle of chlorine. Organisms capable of growth using perchlorate or chlorate as respiratory electron acceptors are also interesting for applications in biotreatment of oxochlorate-containing effluents or bioremediation of contaminated areas. In this review, we discuss the reactions of oxochlorate respiration, the corresponding enzymes, and the relation to respiratory electron transport that can contribute to a proton gradient across the cell membrane. Enzymes specific for oxochlorate respiration are oxochlorate reductases and chlorite dismutase. The former belong to DMSO reductase family of molybdenum-containing enzymes. The heme protein chlorite dismutase, which decomposes chlorite into chloride and molecular oxygen, is only distantly related to other proteins with known functions. Pathways for electron transport may be different in perchlorate and chlorate reducers, but appear in both cases to be similar to pathways found in other respiratory systems.

sted, utgiver, år, opplag, sider
Elsevier, 2013
Emneord
Perchlorate reductase, Chlorate reductase, Chlorite dismutase, Respiration, Cytochrome, Electron transport
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:kau:diva-14068 (URN)10.1016/j.bbabio.2012.06.010 (DOI)000314440200010 ()22735192 (PubMedID)
Tilgjengelig fra: 2012-06-29 Laget: 2012-06-29 Sist oppdatert: 2019-12-04bibliografisk kontrollert
Hellberg Lindqvist, M., Nilsson, T. & Rova, M. (2013). Regulation of genes involved in microbial degradation of chlorate in the chlorate-respiring bacterium Ideonella dechloratans.. In: : . Paper presented at 5th Congress of European Microbiologists (FEMS 2013), Leipzig, Germany, July 21-25, 2013. (pp. 312-312).
Åpne denne publikasjonen i ny fane eller vindu >>Regulation of genes involved in microbial degradation of chlorate in the chlorate-respiring bacterium Ideonella dechloratans.
2013 (engelsk)Konferansepaper, Poster (with or without abstract) (Annet vitenskapelig)
Abstract [en]

Regulation of genes involved in microbial degradation of chlorate in the chlorate-respiring bacterium Ideonella dechloratans

Ideonella dechloratans is a facultative anaerobe and can use both oxygen and chlorate as terminal electron acceptors. Chlorate metabolism involves two enzymes; chlorate reductase (Clr) and chlorite dismutase (Cld). The genes are located in a cluster for chlorate metabolism that also includes the genes for a cytochrome c and a mob B gene. A possible function of the cyt c gene is electron transport during chlorate reduction but so far no corresponding protein has been found. Our aim is to study the expression and possible regulation of Cld and Clr during aerobic and anaerobic metabolism and to examine if the cytochrome c is expressed in I. dechloratans. We have previously reported expression of Clr and Cld, measured both at the mRNA level and as enzyme activities (1). In order to examine sequences important for gene regulation the upstream regions of Clr and Cld were cloned and inserted in a reporter vector and transformed into E. coli XL-1 Blue. The expression of the cyt c gene was analyzed with qRT-PCR in RNA preparations from cells grown under different growth conditions; aerobically or anaerobically. Our results show that the cloned upstream regions of Clr and Cld include functional promoter sequences and that cyt c is expressed in I. dechloratans with increased levels at growth without an external oxygen supply.

1.            Lindqvist, M. H., N. Johansson, T. Nilsson, and M. Rova. 2012. Expression of Chlorite Dismutase and Chlorate Reductase in the Presence of Oxygen and/or Chlorate as the Terminal Electron Acceptor in Ideonella dechloratans. Appl. Environ. Microbiol. 78:4380-4385.

 

HSV kategori
Identifikatorer
urn:nbn:se:kau:diva-33948 (URN)
Konferanse
5th Congress of European Microbiologists (FEMS 2013), Leipzig, Germany, July 21-25, 2013.
Tilgjengelig fra: 2014-10-02 Laget: 2014-10-02 Sist oppdatert: 2017-12-06bibliografisk kontrollert
Hellberg Lindqvist, M., Nilsson, T. & Rova, M. (2012). Expression of chlorate reductase and chlorite dismutase in the chlorate-respiring bacterium Ideonella dechloratans. In: : . Paper presented at Electron transfer at the microbe-mineral interface, a Biochemical Society focused meeting. University of East Anglia, Great Britain, 2-4 April 2012. (pp. P043).
Åpne denne publikasjonen i ny fane eller vindu >>Expression of chlorate reductase and chlorite dismutase in the chlorate-respiring bacterium Ideonella dechloratans
2012 (engelsk)Konferansepaper, Poster (with or without abstract) (Annet vitenskapelig)
HSV kategori
Identifikatorer
urn:nbn:se:kau:diva-15050 (URN)
Konferanse
Electron transfer at the microbe-mineral interface, a Biochemical Society focused meeting. University of East Anglia, Great Britain, 2-4 April 2012.
Tilgjengelig fra: 2012-09-28 Laget: 2012-09-28 Sist oppdatert: 2017-12-06bibliografisk kontrollert
Hellberg Lindqvist, M., Johansson, N., Nilsson, T. & Rova, M. (2012). Expression of Chlorite Dismutase and Chlorate Reductase in the Prescence of Oxygen and/or Chlorate as the Terminal Electron Acceptor in Ideonella dechloratans. Applied and Environmental Microbiology, 78(12), 4380-4385
Åpne denne publikasjonen i ny fane eller vindu >>Expression of Chlorite Dismutase and Chlorate Reductase in the Prescence of Oxygen and/or Chlorate as the Terminal Electron Acceptor in Ideonella dechloratans
2012 (engelsk)Inngår i: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 78, nr 12, s. 4380-4385Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

The ability of microorganisms to perform dissimilatory (per)chlorate reduction is, for most species, known to be oxygen sensitive. Consequently, bioremediation processes for the removal of oxochlorates will be disturbed if oxygen is present. We measured the expression of chlorite dismutase and chlorate reductase in the presence of different terminal electron acceptors in the chlorate reducer Ideonella dechloratans. Enzyme activity assays and mRNA analyses by real-time quantitative reverse transcription (qRT)-PCR were performed on cell extracts from cells grown aerobically with and without chlorate and on cells grown anaerobically in the presence of chlorate. Our results showed that both chlorite dismutase and chlorate reductase are expressed during aerobic growth. However, transfer to anaerobic conditions with chlorate resulted in significantly enhanced enzyme activities and mRNA levels for both enzymes. Absence of oxygen was necessary for the induction to occur, since chlorate addition under aerobic conditions produced neither increased enzyme activities nor higher relative levels of mRNA. For chlorite dismutase, the observed increase in activity was on the same order of magnitude as the increase in the relative mRNA level, indicating gene regulation at the transcriptional level. However, chlorate reductase showed about 200 times higher enzyme activity in anaerobically induced cells, whereas the increase in mRNA was only about 10-fold, suggesting additional mechanisms influence the enzyme activity.

sted, utgiver, år, opplag, sider
American Society for Microbiology, 2012
HSV kategori
Identifikatorer
urn:nbn:se:kau:diva-13406 (URN)10.1128/AEM.07303-11 (DOI)000304788500042 ()
Tilgjengelig fra: 2012-05-29 Laget: 2012-05-29 Sist oppdatert: 2018-07-18bibliografisk kontrollert
Hellberg Lindqvist, M., Nilsson, T. & Rova, M. (2012). Expression of the gene cluster for chlorate metabolism in the chlorate-respiring bacterium Ideonella dechloratans. In: Friedrich T., Einsle O., Gräber P. (Ed.), Biochimica et Biophysica Acta Bioenergetics, Volume 1817, Supplement, October 2012: EBEC Abstract Book. Paper presented at 17th European Bioenergetics Conference (EBEC 2012). Freiburg, Germany, 15 - 20 September, 2012 (pp. S157-S158). Frankfurt
Åpne denne publikasjonen i ny fane eller vindu >>Expression of the gene cluster for chlorate metabolism in the chlorate-respiring bacterium Ideonella dechloratans
2012 (engelsk)Inngår i: Biochimica et Biophysica Acta Bioenergetics, Volume 1817, Supplement, October 2012: EBEC Abstract Book / [ed] Friedrich T., Einsle O., Gräber P., Frankfurt, 2012, s. S157-S158Konferansepaper, Poster (with or without abstract) (Annet vitenskapelig)
Abstract [en]

Ideonella dechloratans is a facultative anaerobe able to use chlorate as a terminal electron acceptor under anaerobic conditions. Two enzymes are necessary for the decomposition of chlorate to chloride and molecular oxygen; chlorate reductase (Clr) and chlorite dismutase (Cld).  The genes for these two enzymes are close to each other in the genome and form, together with a cytochrome c and a mob B gene, a gene cluster for chlorate metabolism. The localization of the cyt c gene suggests a function in electron transport during chlorate reduction but the corresponding protein has not been found. We have addressed the questions of how the expression of Cld and Clr is regulated during the aerob/anaerob switch and if the cyt c gene is expressed in I. dechloratans. The enzyme activities of Cld and Clr were measured in extracts from cells grown at different conditions; aerobically or anaerobically [1]. Both enzymes were found to be active in all samples and the activity increased upon transfer of the cells from aerobic to anaerobic conditions, by five times for Cld and more than 200 times for Clr. Relative mRNA levels of Cld and Clr were determined by qRT-PCR in RNA preparations from cells grown under the same conditions as for the enzyme activity measurements. mRNA from both genes was detected in all preparations but with ten times higher levels in samples from anaerobic conditions. This increase in mRNA level is on the same scale as the increase in enzyme activity for Cld but accounts for less than a tenth of the activity enhancement seen for Clr.  A possible effect of chlorate was tested by the addition of chlorate under aerobic conditions but this resulted in neither increased enzyme activities nor increased mRNA levels. qRT-PCR was performed with primers specific for the cyt c gene and this gene was also found to be expressed at both aerobic and anaerobic conditions. In summary, the results show that chlorate respiration is activated by anaero­biosis but not by chlorate in I. dechloratans and that this activation occurs at the tran­scriptional level. Due to the much larger increase in enzyme activity compared to the increase in mRNA level, the activity of Clr also seems to be effected by other mechanisms. Detection of cyt c mRNA suggests that its gene product can be found and the function investigated.

[1] Hellberg Lindqvist M, Johansson N, Nilsson T, Rova M (2012) Appl. Environ. Microbiol. 78: 4380-4385

sted, utgiver, år, opplag, sider
Frankfurt: , 2012
HSV kategori
Identifikatorer
urn:nbn:se:kau:diva-15049 (URN)
Konferanse
17th European Bioenergetics Conference (EBEC 2012). Freiburg, Germany, 15 - 20 September, 2012
Tilgjengelig fra: 2012-09-28 Laget: 2012-09-28 Sist oppdatert: 2017-12-06bibliografisk kontrollert
Hellberg Lindqvist, M., Nilsson, T. & Rova, M. (2012). Expression of the gene cluster for chlorate metabolism in the chlorate-respiring bacterium Ideonella dechloratans. Biochimica et Biophysica Acta - Bioenergetics, 1817, 157-158
Åpne denne publikasjonen i ny fane eller vindu >>Expression of the gene cluster for chlorate metabolism in the chlorate-respiring bacterium Ideonella dechloratans
2012 (engelsk)Inngår i: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1817, s. 157-158Artikkel i tidsskrift, Meeting abstract (Fagfellevurdert) Published
Abstract [en]

Ideonella dechloratans is a facultative anaerobe able to use chlorate as a terminal electron acceptor under anaerobic conditions. Two enzymes are necessary for the decomposition of chlorate to chloride and molecular oxygen; chlorate reductase (Clr) and chlorite dismutase (Cld). The genes for these two enzymes are close to each other in the genome and form, together with a cytochrome c and a mob B gene, a gene cluster for chlorate metabolism. The localization of the cyt c gene suggests a function in electron transport during chlorate reduction but the corresponding protein has not been found. We have addressed the questions of how the expression of Cld and Clr is regulated during the aerob/anaerob switch and if the cyt c gene is expressed in I. dechloratans. The enzyme activities of Cld and Clr were measured in extracts from cells grown at different conditions; aerobically or anaerobically [1]. Both enzymes were found to be active in all samples and the activity increased upon transfer of the cells from aerobic to anaerobic conditions, by five times for Cld and more than 200 times for Clr. Relative mRNA levels of Cld and Clr were determined by qRT-PCR in RNA preparations from cells grown under the same conditions as for the enzyme activity measurements. mRNA from both genes was detected in all preparations but with ten times higher levels in samples from anaerobic conditions. This increase in mRNA level is on the same scale as the increase in enzyme activity for Cld but accounts for less than a tenth of the activity enhancement seen for Clr. A possible effect of chlorate was tested by the addition of chlorate under aerobic conditions but this resulted in neither increased enzyme activities nor increased mRNA levels. qRT-PCR was performed with primers specific for the cyt c gene and this gene was also found to be expressed at both aerobic and anaerobic conditions. In summary, the results show that chlorate respiration is activated by anaerobiosis but not by chlorate in I. dechloratans and that this activation occurs at the transcriptional level. Due to the much larger increase in enzyme activity compared to the increase in mRNA level, the activity of Clr also seems to be effected by other mechanisms. Detection of cyt c mRNA suggests that its gene product can be found and the function investigated.

sted, utgiver, år, opplag, sider
Elsevier, 2012
HSV kategori
Forskningsprogram
Biomedicinsk vetenskap; Kemi
Identifikatorer
urn:nbn:se:kau:diva-38481 (URN)10.1016/j.bbabio.2012.06.413 (DOI)000308525400387 ()
Tilgjengelig fra: 2016-01-22 Laget: 2015-11-23 Sist oppdatert: 2019-12-04bibliografisk kontrollert
Hellberg, M., Nilsson, T., Rova, M. & Johansson, N. (2010). Regulation of the genes for chlorate reductase (Clr) and chlorite dismutase (Cld) in the chlorate-respiring bacterium Ideonella dechloratans. In: FEBS Journal 277(2010) Supplement 1. Poster presentations: . Paper presented at 35th FEBS Congress, Gothenburg, Sweden,June 26-July 1, 2010. (pp. B4.62.). Wiley-Blackwell
Åpne denne publikasjonen i ny fane eller vindu >>Regulation of the genes for chlorate reductase (Clr) and chlorite dismutase (Cld) in the chlorate-respiring bacterium Ideonella dechloratans
2010 (engelsk)Inngår i: FEBS Journal 277(2010) Supplement 1. Poster presentations, Wiley-Blackwell , 2010, s. B4.62.-Konferansepaper, Poster (with or without abstract) (Annet vitenskapelig)
Abstract [en]

Enzyme activities and mRNA levels of chlorate reductase and chlorite dismutase was investigated in whole cell extracts of Ideonella dechloratans grown under different growth conditions. This bacterium grows well both at aerobic and anaerobic conditions, using oxygen and chlorate, respectively, as a terminal electron acceptor. It was found that preparations from cells grown in the absence of chlorate under aerobic conditions showed activity of both chlorate reductase, measured as chlorate dependent reduction of methyl viologen, and chlorite dismutase, measured as chlorite dependent oxygen production. At aerobic growth conditions, the addition of chlorate resulted in an increased activity of chlorate reductase. The highest activity of chlorate reductase was found in preparations from cells grown anaerobically in the presence of chlorate. No increase in enzyme activity could be detected for chlorite dismutase during anaerobic or aerobic growth in the presence of chlorate, compared to aerobic growth in the absence of chlorate. The mRNA levels for Clr and Cld, measured by real-time quantitative PCR using 16SrRNA as an intern standard, was found to be equal in preparations from cells grown anaerobically in the presence of chlorate compared to cells grown under aerobic conditions in the absence of chlorate. The results suggest that, in I. dechloratans, the activity of chlorate reductase is up-regulated by at least two factors, anaerobiosis and the presence of chlorate. Interestingly, the results also indicate that the studied regulation occurs at post-transcriptional level, while most examples of oxygen regulation in bacteria are reported to occur at transcriptional level.  

sted, utgiver, år, opplag, sider
Wiley-Blackwell, 2010
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:kau:diva-10152 (URN)000278565100598 ()
Konferanse
35th FEBS Congress, Gothenburg, Sweden,June 26-July 1, 2010.
Tilgjengelig fra: 2012-02-08 Laget: 2012-02-08 Sist oppdatert: 2017-12-06bibliografisk kontrollert
Rova, M. (1999). Protection of photosystem II from Photodamage during the Assembly of the Water Oxidizing Complex. Ph.D. Thesis, Lund University
Åpne denne publikasjonen i ny fane eller vindu >>Protection of photosystem II from Photodamage during the Assembly of the Water Oxidizing Complex
1999 (engelsk)Inngår i: Ph.D. Thesis, Lund UniversityArtikkel i tidsskrift (Fagfellevurdert)
sted, utgiver, år, opplag, sider
Lund: , 1999
HSV kategori
Forskningsprogram
Kemi
Identifikatorer
urn:nbn:se:kau:diva-22665 (URN)
Tilgjengelig fra: 2013-01-22 Laget: 2013-01-22 Sist oppdatert: 2017-12-06
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0002-0024-5302