Crystal structure of 1′-OH-carotenoid 3,4-desaturase from Nonlabens dokdonensis DSW-6

Ahn, Joo‐Myung; Kim, Kyungjin

doi:10.1016/j.enzmictec.2015.05.005

Cited by 11 publications

(11 citation statements)

References 40 publications

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“…However, observed carotenoid degradation in fruit and vegetable juice was small (16-25 %). The apparent increase of total carotenoid content (∼20 %) in acidified carrot juice may be due to enhanced solubility of crystallized carotenoids present in the vacuoles of plant material (5) . While our findings confirm the notion that carotenoids are pH sensitive all observed variation were less than 25 %.…”

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confidence: 99%

Effect of pH on the chemical stability of carotenoids in juice

2016

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Carotenoids are abundantly present in fruits and vegetables and are considered beneficial for human health. Although carotenoids are inherently unstable and degradation occurs during food preparation and storage, bioavailability of β-carotene from processed foods, such as carrot juice, can be up to 70 % higher as from raw carrots (1) . Thus, well-chosen food processing techniques can increase health benefits of fruit and vegetables. During juice and smoothie preparation, organic acids are released from sheered plant cells (2) . Carotenoids are sensitive to environmental factors such as light, temperature, oxygen as well to acidic conditions (3) . This study investigated the effect of pH on carotenoid stability in juice.Freshly prepared carrot juice (pH 6·07) was adjusted to pH 8, 7, 6, 5, 4 and 3 using citric acid or NaOH and stored at 4°C for 4 days. Juice samples were freeze-dried and total carotenoids extracted and quantified as previously described (4) . Neutral and slightly basic conditions (pH 8 and 7) reduced total carotenoid content by 26 % (p < 0·05) and acidic conditions (pH 6, 5, 4 and 3) increased the measured total carotenoid content in carrot juice by 18 %, 22 %, 27 % and 22 % respectively (p < 0·05) (Figure 1).When fresh fruit and vegetable juices (carrot, lemon, orange and apple) were blended to attain a pH of 3·15, 3·98 and 4·95, no carotenoid degradation was observed after 8 day storage at 4°C. A pH of 3·15 however resulted in a 16 % reduction of total carotenoids (p < 0·05) (Figure 2).These findings indicate that carotenoids in fresh juices were sensitive to pH. However, observed carotenoid degradation in fruit and vegetable juice was small (16-25 %). The apparent increase of total carotenoid content (∼20 %) in acidified carrot juice may be due to enhanced solubility of crystallized carotenoids present in the vacuoles of plant material (5) . While our findings confirm the notion that carotenoids are pH sensitive all observed variation were less than 25 %.

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confidence: 99%

Effect of pH on the chemical stability of carotenoids in juice

2016

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“…To understand the correlation between the structural changes and the observed activity of mutant CrtI RS , an in silico model of CrtI RS was created using the I-TASSER program [29] with the Protein Data Bank (PDB) templates of Nonlabens dokdonensis DSW-6 γ-carotenoid desaturase (4REP, [30]) and Pantoea ananatis phytoene desaturase (4DGK, [18]) (Figure 4a). As FAD, a redox-active cofactor, is present in the active site region of CrtI RS , in silico ligand docking was simulated using COACH-D [31] with the PDB of FAD binding residues of Pseudomonas savastanoi pv.…”

Section: Structural Evaluation Of Mutant Crtirs Using Computational Model Analysismentioning

confidence: 99%

“…To compare the functional differences of mutant CrtI enzymes, protein structures of CrtI mutants were computationally predicted using I-TASSER [29]. Two protein templates were used to construct CrtI protein models: γ-carotenoid desaturase (PDB ID: 4repA) from N. dokdonensis DSW-6 [30] and phytoene desaturase (PDB ID: 4dgkA) from P. ananatis [18]. Starting with the protein structures, FAD was docked into the crystal structures using COACH-D [31].…”

Section: Computational Modeling Of Phytoene Desaturasementioning

confidence: 99%

Hot Spots of Phytoene Desaturase from Rhodobacter sphaeroides Influencing the Desaturation of Phytoene

2021

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Phytoene desaturase (CrtI, E.C. 1.3.99.31) shows variable desaturation activity, thereby introducing different numbers of conjugated double bonds (CDB) into the substrate phytoene. In particular, Rhodobacter sphaeroides CrtI is known to introduce additional 6 CDBs into the phytoene with 3 CDBs, generating neurosporene with 9 CDBs. Although in-depth studies have been conducted on the function and phylogenetic evolution of CrtI, little information exists on its range of CDB-introducing capabilities. We investigated the relationship between the structure and CDB-introducing capability of CrtI. CrtI of R. sphaeroides KCTC 12085 was randomly mutagenized to produce carotenoids of different CDBs (neurosporene for 9 CDBs, lycopene for 11 CDBs, and 3,4-didehydrolycopene for 13 CDBs). From six CrtI mutants producing different ratios of neurosporene/lycopene/3,4-didehydrolycopene, three amino acids (Leu163, Ala171, and Ile454) were identified that significantly determined carotenoid profiles. While the L163P mutation was responsible for producing neurosporene as a major carotenoid, A171P and I454T produced lycopene as the major product. Finally, according to the in silico model, the mutated amino acids are gathered in the membrane-binding domain of CrtI, which could distantly influence the FAD binding region and consequently the degree of desaturation in phytoene.

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“…The catalytic domain belongs to the Rossmann-fold family structure, consisting of a core height-stranded β-sheet flanked by four α-helices. In our case, the catalytic domain also comprised of residues Gly128-Ser129-Gly130-Pro131-Ser132-Gly133, known as a G-x-G-x-x-G motif, for nucleotide-binding [54]. Because no structure has been reported in the LCYB family, the crystal structure of geranylgeranyl reductase from a Sulfolobus acidocaldarius strain, which displays a 27% sequence identity with D. salina LCYB, was used as a template, as described previously by [16].…”

Section: Overall 3d Model Of D Salina Lcybmentioning

confidence: 99%

Carotenoids Overproduction in Dunaliella Sp.: Transcriptional Changes and New Insights through Lycopene β Cyclase Regulation

et al. 2019

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Dunaliella is a green microalga known for its ability to produce high levels of carotenoids under well-defined growing conditions. Molecular responses to the simultaneous effect of increasing salinity, light intensity and decrease of nitrogen availability were investigated in terms of their effect on different metabolic pathways (isoprenoids synthesis, glycolysis, carbohydrate use, etc.) by following the transcriptional regulation of enolase (ENO), 1-deoxy-D-xylulose 5-phosphate synthase (DXS), lycopene β-cyclase (LCYB), carotene globule protein (CGP), chloroplast-localized heat shock protein (HSP70), and chloroplast ribulose phosphate-3-epimerase (RPE) genes. The intracellular production of carotenoid was increased five times in stressed Dunaliella cells compared to those grown in an unstressed condition. At transcriptional levels, ENO implicated in glycolysis, and revealing about polysaccharides degradation, showed a two-stage response during the first 72 h. Genes directly involved in β-carotene accumulation, namely, CGP and LCYB, revealed the most important increase by about 54 and 10 folds, respectively. In silico sequence analysis, along with 3D modeling studies, were performed to identify possible posttranslational modifications of CGP and LCYB proteins. Our results described, for the first time, their probable regulation by sumoylation covalent attachment as well as the presence of expressed SUMO (small ubiquitin-related modifier) protein in Dunaliella sp.

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Crystal structure of 1′-OH-carotenoid 3,4-desaturase from Nonlabens dokdonensis DSW-6

Cited by 11 publications

References 40 publications

Effect of pH on the chemical stability of carotenoids in juice

Effect of pH on the chemical stability of carotenoids in juice

Hot Spots of Phytoene Desaturase from Rhodobacter sphaeroides Influencing the Desaturation of Phytoene

Carotenoids Overproduction in Dunaliella Sp.: Transcriptional Changes and New Insights through Lycopene β Cyclase Regulation

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