Presence Of Choline Research Articles

Differential effects of choline on TLR2/4 mediated signaling through possible regulation of Toll-interacting protein in hepatocellular carcinoma cell lines

Abstract Objectives Toll-like receptor (TLR) mediated inflammatory status plays an important role in development and progression of hepatocellular carcinoma (HCC). Toll-interacting protein (TOLLIP) has an inhibitory effect on TLR-mediated inflammatory signalling and expression profile of TOLLIP varies between malignancies including HCC. Cholinergic anti-inflammatory pathway (CAP) is an endogenous mechanism that controls inflammatory status via α7nicotinic acetylcholine receptors (α7nAChR). This study aims to investigate the effect of CAP-acting agent choline on TOLLIP and its related TLR-mediated inflammatory response in HCC cells with distinct differentiation stages. Methods The expression patterns of α7nAChR, TLR2/4, TOLLIP, IL6, NFkB genes were evaluated by RT-PCR and ELISA in the presence of choline, along with the real-time cell proliferation and migration in HEP3B and SNU449 HCC cell lines. The interaction between choline and TOLLIP assessed by using in-silico analyses. Results Choline downregulated TOLLIP in Hep3B and SNU449 cells. However, the expressions of α7nAChR, NF-κB, IL-6, TLR2 and TLR4 showed a decreased pattern in well differentiated HEP3B cells, while an increased pattern in poorly differentiated SNU449 cells. Conclusions Choline might exert differential effects in TLR2/4-dependent signalling based on the differentiation stages of the HCC cells, suggesting its potential therapeutic effects in earlier stages of HCC which might be result of its partial modulation of TOLLIP.

Structural basis of lipid head group entry to the Kennedy pathway by FLVCR1.

Phosphatidylcholine and phosphatidylethanolamine, the two most abundant phospholipids in mammalian cells, are synthesized de novo by the Kennedy pathway from choline and ethanolamine, respectively1-6. Despite the essential roles of these lipids, the mechanisms that enable the cellular uptake of choline and ethanolamine remain unknown. Here we show that the protein encoded by FLVCR1, whose mutation leads to the neurodegenerative syndrome posterior column ataxia and retinitis pigmentosa7-9, transports extracellular choline and ethanolamine into cells for phosphorylation by downstream kinases to initiate the Kennedy pathway. Structures of FLVCR1 in the presence of choline and ethanolamine reveal that both metabolites bind to a common binding site comprising aromatic and polar residues. Despite binding to a common site, FLVCR1 interacts in different ways with the larger quaternary amine of choline in and with the primary amine of ethanolamine. Structure-guided mutagenesis identified residues that are crucial for the transport of ethanolamine, but dispensable for choline transport, enabling functional separation of the entry points into the two branches of the Kennedy pathway. Altogether, these studies reveal how FLVCR1 is a high-affinity metabolite transporter that serves as the common origin for phospholipid biosynthesis by two branches of the Kennedy pathway.

Susceptibility of Legionella gormanii Membrane-Derived Phospholipids to the Peptide Action of Antimicrobial LL-37-Langmuir Monolayer Studies.

LL-37 is the only member of the cathelicidin-type host defense peptide family in humans. It exhibits broad-spectrum bactericidal activity, which represents a distinctive advantage for future therapeutic targets. The presence of choline in the growth medium for bacteria changes the composition and physicochemical properties of their membranes, which affects LL-37's activity as an antimicrobial agent. In this study, the effect of the LL-37 peptide on the phospholipid monolayers at the liquid-air interface imitating the membranes of Legionella gormanii bacteria was determined. The Langmuir monolayer technique was employed to prepare model membranes composed of individual classes of phospholipids-phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), cardiolipin (CL)-isolated from L. gormanii bacteria supplemented or non-supplemented with exogenous choline. Compression isotherms were obtained for the monolayers with or without the addition of the peptide to the subphase. Then, penetration tests were carried out for the phospholipid monolayers compressed to a surface pressure of 30 mN/m, followed by the insertion of the peptide into the subphase. Changes in the mean molecular area were observed over time. Our findings demonstrate the diversified effect of LL-37 on the phospholipid monolayers, depending on the bacteria growth conditions. The substantial changes in membrane properties due to its interactions with LL-37 enable us to propose a feasible mechanism of peptide action at a molecular level. This can be associated with the stable incorporation of the peptide inside the monolayer or with the disruption of the membrane leading to the removal (desorption) of molecules into the subphase. Understanding the role of antimicrobial peptides is crucial for the design and development of new strategies and routes for combating resistance to conventional antibiotics.

Understanding the Molecular Basis for Homodimer Formation of the Pneumococcal Endolysin Cpl-1.

The rise of multi-drug-resistant bacteria that cannot be treated with traditional antibiotics has prompted the search for alternatives to combat bacterial infections. Endolysins, which are bacteriophage-derived peptidoglycan hydrolases, are attractive tools in this fight. Several studies have already demonstrated the efficacy of endolysins in targeting bacterial infections. Endolysins encoded by bacteriophages that infect Gram-positive bacteria typically possess an N-terminal catalytic domain and a C-terminal cell-wall binding domain (CWBD). In this study, we have uncovered the molecular mechanisms that underlie formation of a homodimer of Cpl-1, an endolysin that targets Streptococcus pneumoniae. Here, we use site-directed mutagenesis, analytical size exclusion chromatography, and analytical ultracentrifugation to disprove a previous suggestion that three residues at the N-terminus of the CWBD are involved in the formation of a Cpl-1 dimer in the presence of choline in solution. We conclusively show that the C-terminal tail region of Cpl-1 is involved in formation of the dimer. Alanine scanning mutagenesis generated various tail mutant constructs that allowed identification of key residues that mediate Cpl-1 dimer formation. Finally, our results allowed identification of a consensus sequence (FxxEPDGLIT) required for choline-dependent dimer formation─a sequence that occurs frequently in pneumococcal autolysins and endolysins. These findings shed light on the mechanisms of Cpl-1 and related enzymes and can be used to inform future engineering efforts for their therapeutic development against S. pneumoniae.

Deep Eutectic Solvent (DES) Mediated Multicomponent Synthesis of 4- thiazolidinone-5-carboxylic Acid: A Green Chemistry Approach

Background: The 4-thiazolidinone-5-carboxylic acid and its derivatives have diverse applications in agriculture, industrial and pharmaceutical fields. Therefore, the synthesis of this heterocyclic compound attracted much attention from researchers with green chemistry protocols. In this research work, we have introduced the green protocol for the synthesis of 4-thiazolidinone- 5-carboxylic acid by keeping the parameters in mind like cost-effective, environmentally benign, short reaction time and easy work-up procedure. Methods: Initially, we irradiated the mixture of substituted aldehyde, thiosemicarbazide and furan 2-5-dione in the presence of choline chloride-thiourea-based Deep Eutectic Solvent [DES] as a green medium. The reaction optimization was performed in different solvents like ethanol, glycerol, and PEG-400. Results: The DES, which was used as a green solvent, produced an excellent result in context to short reaction time, yield, easy workup, mild reaction condition and cost-effective protocol. All the results are discussed. Conclusion: The DES-mediated synthesis of 4-thiazolidinone-5-carboxylic acid is found to be an excellent protocol, which followed green chemistry principles. This method has specific features like mild reaction conditions, environmentally benign, cost-effective and easy workup procedure.

Enhancement of bactericidal effect of Chlorhexidine using choline augmentation as a natural additive

The long-term use of Chlorhexidine (CHG) at high concentrations has detrimental effects on health and the environment. This research was aimed to evaluate the antibacterial capacity of CHG in the presence of choline as a natural additive to reduce the amount CHG required for the activity. The newly obtained formulation was evaluated for its stability and efficiency under physicochemical stresses. The checkerboard test was also performed to evaluate the type of CHG-additive interaction in a combinational state. The MIC of CHG was reduced up to five-fold in combination with choline at the concentration of 50mg/L and five log cfu/mL at 3 minutes of exposure. Chlorhexidine activity in combination with choline was preserved 20% more in the presence of interfering substances. The activity between CHG and choline was demonstrated as synergistic with FICI of 0.375. At sub MIC concentrations of both CHG (≤20 mg/L) and choline (≤6 mg/L) the observed interaction was synergy. While the significant interaction at high concentrations for both compounds was indifferent manner. The lysis effect of the CHG 20 mg/L was diminished in the presence of choline. Our suggested CHG formulation demonstrated rapid antimicrobial efficacy which can be a useful adjunct to infection control strategies currently employed in healthcare facilities. In conclusion, CHG can be combined with natural compounds as additives for enhanced synergistic antimicrobial activity.

Spironolactone hyaluronic acid enriched cerosomes (HAECs) for topical management of hirsutism: in silico studies, statistical optimization, ex vivo, and in vivo studies

Spironolactone (SP) is a potassium sparing diuretic with antiandrogenic properties. This study aimed at formulating SP into hyaluronic acid enriched cerosomes (HAECs) for topical management of hirsutism. HAECs were prepared by ethanol injection method, according to D-optimal design, after a proper in silico study. HAECs were evaluated by measuring their entrapment efficiency (EE%), particle size (PS), and polydispersity index (PDI). Optimal hyaluronic acid enriched cerosomes (OHAECs) were subjected to further in vitro and ex-vivo and in-vivo studies. The in silico study concluded better interactions between SP and phosphatidyl choline in presence of hyaluronic acid (HA) and high stability of their binding in water. The prepared HAECs had acceptable EE%, PS, and PDI values. The statistical optimization process suggested OHAEC containing 10.5 mg ceramide III and 15 mg HA, utilizing Kolliphor® RH40. OHAEC had EE% and PS of 89.3 ± 0.3% and 261.8 ± 7.0 nm, respectively. OHAEC was stable for up to 3 months. It also showed a mixed tubular and vesicular appearance under transmission electron microscope. The ex vivo and in vivo studies concluded better skin deposition and accumulation of SP from OHAEC. The histopathological study demonstrated the safety of OHAEC for topical application. Therefore, OHAEC could be considered as effective system for topical application of SP to manage hirsutism, with prolonged action, coupled with minimized side effects.

One-Pot Synthesis and Antioxidant Properties of Highly Substituted Piperidine Derivatives Promoted by Choline Chloride/Urea

The simple pseudo four-component reaction of 2,7-naphthalenediol, tow molecules of aldehydes and ammonum carboxylates to produce a series of N-acylated and non-acylated highly substituted piperidine derivatives has been carried out in the presence of choline chloride/urea at 80 °C. One-pot reaction, high efficiency, appropriate reaction time, and easy purification of products by simple recrystallization are some of the considerable advantages of this procedure. The produced highly substituted piperidine derivatives were screened for their antioxidant property. The results indicated that the highly substituted piperidine derivative 4h had higher antioxidant properties.

Choline chloride/Oxalic acid (ChCl/Oxa) catalyzed one-pot synthesis of novel azo and sulfonated pyrimido[4,5-b]quinoline derivatives

One-pot synthesis of azo and sulfonated pyrimido[4,5-b]quinoline derivatives was developed by three-component reaction of azo and sulfonated aldehydes, 6-amino-1,3-dimethyluracil, and dimedone or 1,3-cyclohexadione in the presence of choline chloride/oxalic acid (ChCl/Oxa) at 80 °C. The products formed in excellent yields over appropriate reaction times under an environmentally friendly condition. One-pot reaction, high efficiency, and easy purification of products by simple recrystallization are some of the considerable advantages of this procedure.

Effects of Choline Chloride, Copper Sulfate and Zinc Oxide on Long-Term Stabilization of Microencapsulated Vitamins in Premixes for Weanling Piglets.

Simple SummaryVitamins are essential to animal health and need to be obtained from the diet. As a result of the rapid development of the vitamin industry, microencapsulated vitamins are now available as vitamin sources for premix plants, but vitamins are labile nutrients that are sensitive to the chemical and physical factors that decrease their stability. The current literature on the stability of vitamins in vitamin premixes and vitamin/trace mineral premixes is limited. The most recent recommendations for fortification to overcome losses are provided by a technical bulletin from the company BASF (Badische Anilin-und-Soda-Fabrik). This work has served as the foundation for their recommendations for nearly 20 years; however, the matrix of modern premixes has changed, and conclusions derived from previous studies may no longer hold true, because of changes in vitamin production processing (e.g., microencapsulation) and nutritional content [e.g., choline chloride and high concentrations of copper (Cu) and zinc (Zn) for weanling piglets]. Therefore, the objectives of this study were to determine the rate of vitamin retention in vitamin or vitamin/trace mineral (VTM) premixes, characterize the effects of choline chloride and high concentrations of Cu and Zn on the stability of vitamins and evaluate vitamin stability in vitamin and vitamin/trace mineral premixes during storage.Two in vitro experiments were conducted to investigate the effects of choline chloride, copper sulfate (CuSO4) and zinc oxide (ZnO) on the stability of vitamin A (VA), vitamin D3 (VD3), vitamin E (VE), vitamin K3 (VK3), vitamin B1 (VB1), vitamin B2 (VB2), vitamin B6 (VB6), niacin, and pantothenic acid in vitamin and vitamin/trace mineral (VTM) premixes for weanling piglets after 0, 1, 2, 3, 6 and 12 months of premix storage. We developed predicted equations to estimate vitamin retention during storage. Two vitamin premixes (with or without choline) were formulated and stored at 25 °C and 60% humidity to establish the storage stability of vitamin premixes. Additionally, four VTM premixes were used to evaluate the effect of choline chloride (0 vs. 40,000 mg/kg) and trace minerals (Low CuSO4 + ZnO vs. High CuSO4 + ZnO) on vitamin stability in VTM premixes stored at room temperature (22 °C). In general, as storage time increased, residual vitamin activity decreased (p < 0.05). The results confirmed that VD3, VE, VB2, VB6, niacin and pantothenic acid were highly stable during storage, while the retention of VA, VK3 and VB1 was significantly affected by storage time and the presence of choline and high concentrations of Cu and Zn in the premix. After one year of storage, the retention of VE, VB2, VB6 niacin, and pantothenic acid was more than 90% in vitamin and VTM premixes. The retention of VD3 was more than 90% in vitamin premixes and more than 80% in VTM premixes after one year of storage. We conclude that current microencapsulation techniques for vitamin premixes appear to be inadequate to guarantee VA, VK3, and VB1 concentrations in VTM premixes.

Deep Eutectic Solvent Mediated One-Pot Synthesis of Hydrazinyl-4-Phenyl-1,3-Thiazoles

One-pot synthesis of hydrazinyl-4-phenyl-1,3-thiazole derivatives was developed by three-component reaction of various ketones or aldehydes, phenacyl chloride, and thiosemicarbazid in the presence of choline chloride/urea as a deep eutectic solvent (DES) at 70 °C. The products formed in excellent yields over short reaction times under an environmentally friendly condition. This method develops by using an environmentally benign synthetic method along with the use of a cost-effective catalyst. The study of antibacterial activity revealed that the compounds (4j, 4k, 4l, 4m, 4s, and 4t) showed good inhibition toward Escherichia coli.

Phytochemical and anti-inflammatory properties of Scurrula ferruginea (Jack) Danser parasitising on three different host plants elucidated by NMR-based metabolomics.

Scurrula ferruginea (Jack) Danser is a hemi-parasitic shrub that is widely used as a traditional herbal medicine. To elucidate the anti-inflammatory activity of S. ferruginea parasitising on three different hosts of Vitex negundo L., Micromelum minutum (G. Forst.) Wight & Arn. and Tecoma stans (L.) Juss ex HBK., as well as, to determine the metabolite differences related to their anti-inflammatory properties. Two plant parts of S. ferruginea, stems and leaves, were extracted in water. The freeze-dried stem of S. ferruginea grown on T. stans was liquid-liquid partitioned into several solvents. Their potential anti-inflammatory activity was assessed via inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS) and interferon-γ (IFN-γ)-induced RAW 264.7 macrophage cells. The metabolite variation was examined using proton nuclear magnetic resonance (1 H-NMR) combined with multivariate data analysis (MVDA). Scurrula ferruginea stems parasitising on T. stans and V. negundo which were freeze dried exhibited higher anti-inflammatory activity with IC50 values of 114.47±2.96 and 118.87±2.31μg/mL, respectively. The mid-polar ethyl acetate fraction of S. ferruginea hosted on T. stans displayed the highest NO inhibition with 84.80±0.45% at 200μg/mL. Principal component analysis (PCA) indicated notable and clear discriminations among the different plant parts and host plants based on the identified metabolites. Furthermore, partial least squares (PLS) regression model suggested the anti-inflammatory bioactivity might be associated with the presence of choline, isoleucine, catechin, leucine and chlorogenic acid. This study suggests S. ferruginea could serve as a potential anti-inflammatory agent, highlighting the importance of T. stans as the host plant.

Ecofriendly Long Life Nanocomposite Sensors for Determination of Carbachol in Presence of Choline: Application in Ophthalmic Solutions and Biological Fluids.

Several emerging nano scale forms of carbon are showing great promise in electrochemical sensing such as graphene and multi-walled carbon nanotubes (MWCNTs). Herein we present an ecofriendly method to fabricate long life and sensitive ion selective sensors based on graphene and MWCNTs nanocomposites with no need for volatile organic solvents. Both sensors were fabricated, for the analysis of carbachol in ophthalmic solutions, plasma and urine where ion- association complex was formed between cationic carbachol and anionic Sodium tetra phenyl borate (NaTBP) in a ratio 1:1. Both sensors were evaluated according to the IUPAC recommendation data, revealing linear response in the concentration range 10−7 M to 10−2 M with near Nernstian slopes 50.80 ± 5 and 58.14 ± 3 mV/decade and correlation coefficients 0.9992 and 0.9998 for graphene and MWCNTs based sensors, respectively. Both sensors were successfully applied as stability indicating method for the analysis of carbachol in presence of its metabolite choline, in ophthalmic preparations, in plasma and urine showing good recovery percentage values. MWCNTs based sensor showed some advantages over graphene sensor regarding lower limit of detection (LOD), longer life time and higher selectivity towards carbachol. Statistical comparison of the proposed sensors with the official method showed no significant difference for accuracy and precision.

An Efficient Strategy for the Production of Epoxidized Oils: Natural Deep Eutectic Solvent‐Based Enzymatic Epoxidation

AbstractPoor H2O2‐resistance by enzymes is a key bottleneck in the epoxidation process of oil by enzymatic methods. In this study, the stability of three lipases, from Aspergillus oryzae lipase (AOL), Aspergillus fumigatus lipase B (AflB), and marine Janibacter (MAJ1), in the presence of H2O2 was evaluated in different types of natural deep eutectic solvents (NADES). This stability was strengthened significantly in the NADES compared to the buffer. Specifically, AOL retained 84.7% of its initial activity in the presence of choline chloride/sorbitol (1:1 M ratio) and 3 mol L−1 H2O2 after 24 h incubation at 40°C. In addition, the two‐phase epoxidation process was optimized with AOL in ChCl/sorbitol to reach up to 96.8% conversion under the optimized conditions (molar ratio of octanoic acid/H2O2/C=C‐bonds = 0.3:1.5:1, enzyme loading of 15 U g−1 of soybean oil, ChCl/sorbitol content of 70.0% of the weight of hydrophilic phase, and reaction temperature of 50°C). Moreover, the lipase dispersed in NADES retained approximately 66% of its initial activity after being used for seven batch cycles. Overall, NADES‐based enzymatic epoxidation is a feasible and promising strategy for the synthesis of epoxidized oils.

Label-free colorimetric sensor for sensitive detection of choline based on DNAzyme-choline oxidase coupling

Changes in choline levels can be associated with diseases such as Alzheimer, Parkinson, Huntington, fatty liver, interstitial lung abnormalities, autism and so on. Therefore, quantitative determination of choline is important in the biological and clinical analysis. So far, several methods have been investigated for measuring choline in the body fluids, each of which has disadvantages such as the need for specialist ability, complexity, and high cost. For this purpose, a facile and sensitive colorimetric biosensor based on DNAzyme-choline oxidase coupling used for the determination of choline. In this method, the first, choline oxidase produces H2O2 and betaine in the presence of choline and oxygen, then, the DNAzyme converts colorless ABTS into green ABTS+ radicals. Compared to the previous methods, the linear range and the limit of detection of this talented biosensor were 0.1–25 μM and 22 nM. Choline measurement using this biosensor has shown satisfactory selectivity and repeatability. Its recovery was 96.9-103.7%, which shows the reliability of biosensor assay in biological samples. Simplicity, low cost, naked eye, high sensitivity, and precision are the benefits of this biosensor. Taken to gather, the proposed system can be considered as a great biosensor for measuring choline levels especially in point of care diagnostic.

Interaction between repressor Opi1p and ER membrane protein Scs2p facilitates transit of phosphatidic acid from the ER to mitochondria and is essential for INO1 gene expression in the presence of choline

In the yeast Saccharomyces cerevisiae, the Opi1p repressor controls the expression of INO1 via the Opi1p/Ino2p-Ino4p regulatory circuit. Inositol depletion favors Opi1p interaction with both Scs2p and phosphatidic acid at the endoplasmic reticulum (ER) membrane. Inositol supplementation, however, favors the translocation of Opi1p from the ER into the nucleus, where it interacts with the Ino2p-Ino4p complex, attenuating transcription of INO1 A strain devoid of Scs2p (scs2Δ) and a mutant, OPI1FFAT, lacking the ability to interact with Scs2p were utilized to examine the specific role(s) of the Opi1p-Scs2p interaction in the regulation of INO1 expression and overall lipid metabolism. Loss of the Opi1p-Scs2p interaction reduced INO1 expression and conferred inositol auxotrophy. Moreover, inositol depletion in strains lacking this interaction resulted in Opi1p being localized to sites of lipid droplet formation, coincident with increased synthesis of triacylglycerol. Supplementation of choline to inositol-depleted growth medium led to decreased TAG synthesis in all three strains. However, in strains lacking the Opi1p-Scs2p interaction, Opi1p remained in the nucleus, preventing expression of INO1 These data support the conclusion that a specific pool of phosphatidic acid, associated with lipid droplet formation in the perinuclear ER, is responsible for the initial rapid exit of Opi1p from the nucleus to the ER and is required for INO1 expression in the presence of choline. Moreover, the mitochondria-specific phospholipid, cardiolipin, was significantly reduced in both strains compromised for Opi1p-Scs2p interaction, indicating that this interaction is required for the transfer of phosphatidic acid from the ER to the mitochondria for cardiolipin synthesis.

Betaine is accumulated via transient choline dehydrogenase activation during mouse oocyte meiotic maturation

Betaine (N,N,N-trimethylglycine) plays key roles in mouse eggs and preimplantation embryos first in a novel mechanism of cell volume regulation and second as a major methyl donor in blastocysts, but its origin is unknown. Here, we determined that endogenous betaine was present at low levels in germinal vesicle (GV) stage mouse oocytes before ovulation and reached high levels in the mature, ovulated egg. However, no betaine transport into oocytes was detected during meiotic maturation. Because betaine can be synthesized in mammalian cells via choline dehydrogenase (CHDH; EC 1.1.99.1), we assessed whether this enzyme was expressed and active. Chdh transcripts and CHDH protein were expressed in oocytes. No CHDH enzyme activity was detected in GV oocyte lysate, but CHDH became highly active during oocyte meiotic maturation. It was again inactive after fertilization. We then determined whether oocytes synthesized betaine and whether CHDH was required. Isolated maturing oocytes autonomously synthesized betaine in vitro in the presence of choline, whereas this failed to occur in Chdh-/- oocytes, directly demonstrating a requirement for CHDH for betaine accumulation in oocytes. Overall, betaine accumulation is a previously unsuspected physiological process during mouse oocyte meiotic maturation whose underlying mechanism is the transient activation of CHDH.

Autolyse the cell in order to save it? Inducing, then blocking, autolysis as a strategy for delaying cell death in the probiotic Lactobacillus reuteri.

To examine whether choline and its derivatives can be used to preserve viable cells of Lactobacillus reuteri in autolytic models. A phosphate-induced autolytic model in de Man, Rogosa and Sharpe medium (MRS) was used. Viable cell counts were determined by plated on MRS-agar. Choline and hemicholinium-3 (HC-3) significantly blocked autolysis of L. reuteri at 360mM and 4mM, respectively. Viable cell counts corroborated these observations. Importantly, autolytically induced cells treated with choline and hemicholinium-3 were significantly more viable then even non-induced cells. Over-production of a known autolytic protein, spirosin, was not attenuated in the presence of choline and hemicholinium-3. Inducing autolysis and then blocking it with choline and its analogs is a promising approach for retaining the viability of L. reuteri cells.

Molecular Basis of C–N Bond Cleavage by the Glycyl Radical Enzyme Choline Trimethylamine-Lyase

Deamination of choline catalyzed by the glycyl radical enzyme choline trimethylamine-lyase (CutC) has emerged as an important route for the production of trimethylamine, a microbial metabolite associated with both human disease and biological methane production. Here, we have determined five high-resolution X-ray structures of wild-type CutC and mechanistically informative mutants in the presence of choline. Within an unexpectedly polar active site, CutC orients choline through hydrogen bonding with a putative general base, and through close interactions between phenolic and carboxylate oxygen atoms of the protein scaffold and the polarized methyl groups of the trimethylammonium moiety. These structural data, along with biochemical analysis of active site mutants, support a mechanism that involves direct elimination of trimethylamine. This work broadens our understanding of radical-based enzyme catalysis and will aid in the rational design of inhibitors of bacterial trimethylamine production.

Effect dietary choline supplementation on egg quality and serumbiochemical profile in White Pekin Ducks

The aim of the present study was to evaluate the influence of choline in diet (a TMA precursor) on egg quality, serum biochemistry and presence of off flavour in eggs of White Pekin Ducks. 30 White Pekin ducks (45 weeks age) housed in individual cages were subjected to three dietary treatment groups and were. The dietary treatment groups consisted of two levels of choline as TMA precursor viz; 3g/kg diet, 6g/kg diet and a control diet devoid of choline. The results revealed highly significant (P&lt;0.0001) effect of choline on yolk weight and HU than the control. However the other egg quality traits i.,e egg weight, albumen weight, shell weight, albumen index, yolk index, shape index, shell thickness were not influenced. Serum cholesterol and triglycerides were significantly (P&lt;0.0001) reduced in high choline group (6g/kg diet) followed by low choline group (3g/kg diet) and control. The liver enzymes (SGPT and SGOT) were significantly lower (P&lt;0.0001) in both the supplemented groups as compared to control. No significant effect was found for serum total protein and serum glucose levels. Presence of off flavour (fishy flavour) was more evident in the eggs of choline group (6g/kg diet) than the control group. It can be concluded that the presence of choline in the diet had minimal effect on the egg quality parameters of Pekin ducks except for yolk weight and albumen quality, however there was significant reduction in serum total cholesterol and triglycerides levels.