Phragmites australis peroxidases role in the degradation of an azo dye

2007 ◽  
Vol 56 (3) ◽  
pp. 263-269 ◽  
Author(s):  
C.C. Carias ◽  
J.M. Novais ◽  
S. Martins-Dias

Phragmites australis are commonly used in constructed wetlands either for domestic sewage or industrial effluents treatment. The aerobic mineralization mechanisms of Acid Orange 7, AO7, in a Vertical Flow Constructed Wetland (VFCW) planted with P. australis suggest that AO7 degradation pathway may involve enzymes like peroxidases (POD), known to degrade some recalcitrant pollutants. In this context, the aim of this study was to evaluate the role of POD extracted from the VFCW P. australis leaves in the decolourization of AO7, which belongs to the very restricted group of bio-degradable azo dyes and is widely used in the textile industry. Leaves' crude extract (CE) was purified by protein fractioning with ammonium sulphate (20–80%). AO7 (0.14 mM) decolourization rate of each CE fraction was determined using hydrogen peroxide (0.2 mM) as a co-substrate. A maximum specific activity of 6.8 × 10−3 μmol QNNM min−1 mg protein−1 was obtained for the 40–60% fraction. The results obtained suggest that P. australis may be a good candidate for the treatment of AO7 contaminated effluents in a VFCW, as very high removal efficiencies were achieved at pilot scale and in vitro studies leading to the decolourization of the dye, suggesting a positive and active role of P. australis in the removal mechanisms within the VFCW. Moreover, some questions were put forward regarding the participation of other important plant enzymes in the degradation process.

Development ◽  
1982 ◽  
Vol 70 (1) ◽  
pp. 171-187
Author(s):  
A. M. Duprat ◽  
L. Gualandris ◽  
P. Rouge

Lectins (SBA and PSA) were used to provoke crowding and structural modifications of the presumptive ectoderm cell surface in order to investigate the role of the membrane organization of the competent target cells in neural induction. Are specific characteristics of the cell surface essential for this phenomenon to occur? From amphibian gastrulae, it is possible to obtain neural induction in vitro by association of presumptive ectoderm (target cells) with chordamesoderm (inductor tissue): 4 h of contact is sufficient in Pleurodeles waltl for transmission of the inductive signal. Very quickly, the treatment of the normal ectoderm by lectins (SBA-FITC or PSA-FITC) provoked surface modifications. Lectin-treatment (50 µg ml1−, 30 min) of presumptive ectoderm did not result in any neural induction. Lectin-treatment (50 µg ml1−, 30 min) of presumptive ectoderm previous to its association with the natural inductor for 4 h, disturbed the phenomenon: no induction. Similar treatment followed by association with the inductor for 24 h: induction. Treatment of SBA or PSA with their respective hapten inhibitors prior to addition to ectodermal cells completely blocked the suppressive effects on induction. The structural integrity of the membrane of competent target cells is necessary for neural induction to occur. The cell membrane could thus play, directly or indirectly, an active role in the specificity of this process


Author(s):  
Chieko Matsui ◽  
Putu Yuliandari ◽  
Lin Deng ◽  
Takayuki Abe ◽  
Ikuo Shoji

Lysosome incorporate and degrade proteins in a process known as autophagy. There are three types of autophagy; macroautophagy, microautophagy, and chaperone-mediated autophagy (CMA). Although autophagy is considered a nonselective degradation process, CMA is known as a selective degradation pathway. All proteins internalized in the lysosome via CMA contain a pentapeptide KFERQ-motif, also known as a CMA-targeting motif, which is necessary for selectivity. CMA directly delivers a substrate protein into the lysosome lumen using the cytosolic chaperone HSC70 and the lysosomal receptor LAMP-2A for degradation. Hepatitis C virus (HCV) NS5A protein interacts with hepatocyte-nuclear factor 1α (HNF-1α) together with HSC70 and promotes the lysosomal degradation of HNF-1α via CMA, resulting in HCV-induced pathogenesis. HCV NS5A promotes recruitment of HSC70 to the substrate protein HNF-1α. HCV NS5A plays a crucial role in HCV-induced CMA. Further investigations of HCV NS5A-interacting proteins containing CMA-targeting motifs may help to elucidate HCV-induced pathogenesis.


2019 ◽  
Vol 85 (20) ◽  
Author(s):  
Masae Horinouchi ◽  
Hiroyuki Koshino ◽  
Michal Malon ◽  
Hiroshi Hirota ◽  
Toshiaki Hayashi

ABSTRACT Comamonas testosteroni TA441 degrades steroids via aromatization of the A ring, followed by degradation of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid, mainly by β-oxidation. In this study, we revealed that 7β,9α-dihydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostanoic acid-coenzyme A (CoA) ester is dehydrogenated by (3S)-3-hydroxylacyl CoA-dehydrogenase, encoded by scdE (ORF27), and then the resultant 9α-hydroxy-7,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid-CoA ester is converted by 3-ketoacyl-CoA transferase, encoded by scdF (ORF23). With these results, the whole cycle of β-oxidation on the side chain at C-8 of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid is clarified; 9-hydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid-CoA ester is dehydrogenated at C-6 by ScdC1C2, followed by hydration by ScdD. 7β,9α-Dihydroxy-17-oxo-1,2,3,4,10,19-hexanorandrostanoic acid-CoA ester then is dehydrogenated by ScdE to be converted to 9α-hydroxy-17-oxo-1,2,3,4,5,6,10,19-octanorandrostan-7-oic acid-CoA ester and acetyl-CoA by ScdF. ScdF is an ortholog of FadA6 in Mycobacterium tuberculosis H37Rv, which was reported as a 3-ketoacyl-CoA transferase involved in C ring cleavage. We also obtained results suggesting that ScdF is also involved in C ring cleavage, but further investigation is required for confirmation. ORF25 and ORF26, located between scdF and scdE, encode enzymes belonging to the amidase superfamily. Disrupting either ORF25 or ORF26 did not affect steroid degradation. Among the bacteria having gene clusters similar to those of tesB to tesR, some have both ORF25- and ORF26-like proteins or only an ORF26-like protein, but others do not have either ORF25- or ORF26-like proteins. ORF25 and ORF26 are not crucial for steroid degradation, yet they might provide clues to elucidate the evolution of bacterial steroid degradation clusters. IMPORTANCE Studies on bacterial steroid degradation were initiated more than 50 years ago primarily to obtain materials for steroid drugs. Steroid-degrading bacteria are globally distributed, and the role of bacterial steroid degradation in the environment as well as in relation to human health is attracting attention. The overall aerobic degradation of the four basic steroidal rings has been proposed; however, there is still much to be revealed to understand the complete degradation pathway. This study aims to uncover the whole steroid degradation process in Comamonas testosteroni TA441 as a model of steroid-degrading bacteria. C. testosteroni is one of the most studied representative steroid-degrading bacteria and is suitable for exploring the degradation pathway, because the involvement of degradation-related genes can be determined by gene disruption. Here, we elucidated the entire β-oxidation cycle of the cleaved B ring. This cycle is essential for the following C and D ring cleavage.


2019 ◽  
Vol 7 (10) ◽  
pp. 384 ◽  
Author(s):  
Valentina Riva ◽  
Francesca Mapelli ◽  
Evdokia Syranidou ◽  
Elena Crotti ◽  
Redouane Choukrallah ◽  
...  

The microbiome associated with plants used in phytodepuration systems can boost plant growth and services, especially in ecosystems dealing with recalcitrant compounds, hardly removed via traditional wastewater (WW) treatments, such as azo-dyes used in textile industry. In this context, we aimed to study the cultivable microbiome selected by Phragmites australis plants in a Constructed Wetland (CW) in Morocco, in order to obtain candidate inoculants for the phytodepuration of azo-dye contaminated WW. A collection of 152 rhizospheric and endophytic bacteria was established. The strains were phylogenetically identified and characterized for traits of interest in the phytodepuration context. All strains showed Plant Growth Promotion potential in vitro and 67% of them significantly improved the growth of a model plant in vivo compared to the non bacterized control plants. Moreover, most of the isolates were able to grow in presence of several model micropollutants typically found in WW, indicating their potential use in phytodepuration of a wide spectrum of effluents. The six most promising strains of the collection were tested in CW microcosms alone or as consortium: the consortium and two single inocula demonstrated to significantly increase the removal of the model azo-dye Reactive Black 5 compared to the non bacterized controls.


2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Ana Jolly ◽  
Silvia Beatriz Colavecchia ◽  
Bárbara Fernández ◽  
Eloy Fernández ◽  
Silvia Leonor Mundo

Lipoarabinomannan (LAM) is a major glycolipidic antigen on the mycobacterial envelope. The aim of this study was to characterize the humoral immune response induced by immunization with a LAM extract in bovines and to evaluate the role of the generated antibodies in thein vitroinfection of macrophages withMycobacterium aviumsubsp.paratuberculosis(MAP). Sera from fourteen calves immunized with LAM extract or PBS emulsified in Freund's Incomplete Adjuvant and from five paratuberculosis-infected bovines were studied. LAM-immunized calves developed specific antibodies with IgG1 as the predominant isotype. Serum immunoglobulins were isolated and their effect was examined in MAP ingestion and viability assays using a bovine macrophage cell line. Our results show that the antibodies generated by LAM immunization significantly increase MAP ingestion and reduce its intracellular viability, suggesting an active role in this model.


1993 ◽  
Vol 293 (1) ◽  
pp. 181-185 ◽  
Author(s):  
N J Watkins ◽  
A K Campbell

cDNA coding for the Ca(2+)-activated photoprotein aequorin from the jellyfish Aequorea victoria has been engineered to investigate the role of the C-terminal proline residue in bioluminescence. Recombinant aequorin proteins were synthesized by PCR followed by in vitro transcription/translation, and characterized by specific activity, stability, and affinity for coelenterazine. The C-terminal proline residue of aequorin was shown to be essential for the long-term stability of the bound coelenterazine. Aequorin minus proline had only 1% of the specific activity of the wild-type after 2 h, and was virtually inactive after 18 h. The instability of this variant was further demonstrated by re-activating with a coelenterazine analogue (epsilon-coelenterazine), where maximum reactivation was reached in 15 min, and the luminescent activity was almost completely abolished within 3 h. Replacement of the C-terminal proline residue with histidine or glutamic acid decreased the specific activity to 10 and 19% of that of the wild-type respectively. However these variants were also unstable, having t1/2 values of 2.4 h and 2.3 h respectively. Enhancement of the Ca(2+)-independent light emission when proline was replaced by histidine confirmed the stabilizing role of the C-terminal proline. No significant effect of removal of the C-terminal proline was detected on the affinity for coelenterazine.


1982 ◽  
Vol 2 (5) ◽  
pp. 343-349 ◽  
Author(s):  
David A. Hillson ◽  
Jacqueline Anderson

Conclusions The use of diethylpyrocarbonate to inhibit endogenous ribonuclease in sheep pancreas allows the detection of protein-disulphide-isomerase activity in homogenates, at specific activities of up to 4 units/g. This is higher than the specific activity in sheep liver homogenates (about 2 units/g) or in homogenates of other sheep tissues (16). It is thus evident that high levels of protein-disulphide-isomerase activity are present in sheep pancreas. This is consistent both with the postulated general role of protein disulphide-isomerase in protein biosynthesis (10,11) and with the in vitro action of the enzyme on its conventional substrate scrambled ribonuclease, since pancreas is the major site of ribonuclease synthesis.


Reproduction ◽  
2012 ◽  
Vol 143 (4) ◽  
pp. 439-447 ◽  
Author(s):  
S E Racedo ◽  
V Y Rawe ◽  
H Niemann

For successful fertilization by the male gamete, oocyte cytoplasmic organelles such as the Golgi apparatus have to undergo specific changes: the entire process is known as cytoplasmic maturation. The goal of this study was to unravel the dynamics of the Golgi apparatus in bovine oocytes at critical stages ofin vitromaturation, i.e. germinal vesicle (GV), GV breakdown (GVBD), metaphase I (MI) and metaphase II, and to investigate the role of various molecules critically involved therein. The cytoplasmic distribution of proteins was assessed by immunocytochemistry and laser confocal microscopy. We applied specific inhibitors, including nocodazole to unravel the functional role of the microtubular elements; sodium orthovanadate, which primarily inhibits cytoplasmic dynein ATPase activity; monastrol which inhibits the kinesin EG5; and roscovitine to inhibit the kinase cyclin-dependent kinase 2A (CDC2A). Prior to GVBD, the Golgi apparatus was translocated from the centre of the cytoplasm to the cortical area in the periphery, where it underwent fragmentation. A second translocation was observed between GVBD and MI stages, when the Golgi apparatus was moved from the cortex to the centre of the cytoplasm. Incubation with the specific inhibitors revealed that microtubules played an active role in the final localization at GVBD, while CDC2A was essential for Golgi fragmentation at GVBD stage. This partitioning was a precondition for the second movement. In conclusion, for the first time we show basic mechanisms critically involved in the regulation of the dynamic changes of Golgi apparatus during meiosis of the bovine oocyte.


2007 ◽  
Vol 190 (5) ◽  
pp. 1575-1583 ◽  
Author(s):  
Daryl J. Smith ◽  
Marianna A. Patrauchan ◽  
Christine Florizone ◽  
Lindsay D. Eltis ◽  
William W. Mohn

ABSTRACT The 80-kb dit cluster of Burkholderia xenovorans LB400 encodes the catabolism of abietane diterpenoids. This cluster includes ditQ and ditU, predicted to encode cytochromes P450 (P450s) belonging to the poorly characterized CYP226A subfamily. Using proteomics, we identified 16 dit-encoded proteins that were significantly more abundant in LB400 cells grown on dehydroabietic acid (DhA) or abietic acid (AbA) than in succinate-grown cells. A key difference in the catabolism of DhA and AbA lies in the differential expression of the P450s; DitU was detected only in the AbA-grown cells, whereas DitQ was expressed both during growth on DhA and during growth on AbA. Analyses of insertion mutants showed that ditQ was required for growth on DhA, ditU was required for growth on AbA, and neither gene was required for growth on the central intermediate, 7-oxo-DhA. In cell suspension assays, patterns of substrate removal and metabolite accumulation confirmed the role of DitU in AbA transformation and the role of DitQ in DhA transformation. Spectral assays revealed that DitQ binds both DhA (dissociation constant, 0.98 ± 0.01 μM) and palustric acid. Finally, DitQ transformed DhA to 7-hydroxy-DhA in vitro. These results demonstrate the distinct roles of the P450s DitQ and DitU in the transformation of DhA and AbA, respectively, to 7-oxo-DhA in a convergent degradation pathway.


1998 ◽  
Vol 18 (7) ◽  
pp. 3947-3955 ◽  
Author(s):  
Sandrine Roy ◽  
Robert A. McPherson ◽  
Ann Apolloni ◽  
Jun Yan ◽  
Annette Lane ◽  
...  

ABSTRACT 14-3-3 proteins complex with many signaling molecules, including the Raf-1 kinase. However, the role of 14-3-3 in regulating Raf-1 activity is unclear. We show here that 14-3-3 is bound to Raf-1 in the cytosol but is totally displaced when Raf-1 is recruited to the plasma membrane by oncogenic mutant Ras, in vitro and in vivo. 14-3-3 is also displaced when Raf-1 is targeted to the plasma membrane. When serum-starved cells are stimulated with epidermal growth factor, some recruitment of 14-3-3 to the plasma membrane is evident, but 14-3-3 recruitment correlates with Raf-1 dissociation and inactivation, not with Raf-1 recruitment. In vivo, overexpression of 14-3-3 potentiates the specific activity of membrane-recruited Raf-1 without stably associating with the plasma membrane. In vitro, Raf-1 must be complexed with 14-3-3 for efficient recruitment and activation by oncogenic Ras. Recombinant 14-3-3 facilitates Raf-1 activation by membranes containing oncogenic Ras but reduces the amount of Raf-1 that associates with the membranes. These data demonstrate that the interaction of 14-3-3 with Raf-1 is permissive for recruitment and activation by Ras, that 14-3-3 is displaced upon membrane recruitment, and that 14-3-3 may recycle Raf-1 to the cytosol. A model that rationalizes many of the apparently discrepant observations on the role of 14-3-3 in Raf-1 activation is proposed.


Sign in / Sign up

Export Citation Format

Share Document