70-18-8 Usage
Description
Glutathione (GSH) is a tripeptide (γ-glutamylcysteinylglycine) that is widely distributed in both plants and animals. It serves as a nucleophilic co-substrate to glutathione transferases in the detoxification of xenobiotics and is an essential electron donor to glutathione peroxidases in the reduction of hydroperoxides. GSH is also involved in amino acid transport and maintenance of protein sulfhydryl reduction status. The concentration of GSH ranges from a few micromolar in plasma to several millimolar in tissues such as liver.
Uses
Used in Pharmaceutical Industry:
Glutathione is used as a pharmaceutical secondary standard for application in quality control, providing pharma laboratories and manufacturers with a convenient and cost-effective alternative to the preparation of in-house working standards.
Used in Liver Protection:
Glutathione is used as a liver protectant for promoting the role of liver enzyme activity and protecting the liver cell membrane. It has a good curative effect on drug poisoning, alcoholism, and other causes of liver injury, as well as diseases such as cirrhosis of the liver.
Used in Antioxidant Applications:
Glutathione is used as an antioxidant for scavenging free radicals, detoxification, enhancing immunity, anti-aging, anti-cancer, and anti-radiation damage.
Used in Detoxification:
Glutathione is used as a detoxification agent, mainly for the poisoning of heavy metals, acrylonitrile, fluoride, carbon monoxide, and organic solvents.
Used in Skin Care:
Glutathione is used as a skin-lightening or de-pigmenting agent, enhancing the skin's cellular metabolism and oxygen utilization. It protects the fibroblast against free radical-induced oxidation and acts as a powerful antioxidant.
Used in HIV Treatment:
L-Glutathione is used in the treatment of lung diseases for patients who are HIV positive, protecting cancerous cells by conferring resistance to chemotherapeutic drugs.
Used in Wine Production:
Glutathione is used in white wine production, where it plays a role in the fermentation process and contributes to the wine's flavor and quality.
Used in Redox Signaling and Oxidative Stress Protection:
Glutathione is used as a key determinant of redox signaling and protection against oxidative stress, maintaining the proper functioning of the immune system and cellular components.
Features and functions
Glutathione is composed of glutamic acid, cysteine and glycine by peptide bonds condensation of three peptide compounds,which is the most important antioxidant stress of low molecular mercaptan in mammalian cells.We discovered it in 1921 and determined the chemical structure in 1930 , the famous American nutrition health experts said Dr Al sensitive del glutathione is three times the efficiency of the anti-aging amino acid, also known as the antioxidant master of nature, the appearance is colorless transparent thin granular crystal, it is soluble in water, dilute alcohol, liquid ammonia, dimethyl formamide,and it’s insoluble in ethanol, ether, acetone.Its solid character is stable, its aqueous solution is easy oxidized in the air for oxidized glutathione, widely exists in baker's yeast, wheat germ, animal liver, chicken blood, pig blood, tomato, pineapple, cucumber, of which is highest in the wheat germ and liver, content as high as 100~1000 mg/100 g.With antioxidant, scavenging free radicals, detoxification, enhance immunity, anti-aging, anti-cancer, anti radiation damage, and other functions.It also helps white blood cells to kill bacteria and prevent the oxidation of the vitamins C and E, to prevent stroke and cataract formation.In addition, glutathione can bind the carcinogen, than excrete them through the urine in vitro.
The liver is the most important detoxification organs, which contains rich in glutathione (GSH) on the liver function such as synthesis, detoxification, estrogen inactivated protection.It is the first anti-oxidant that the human body is to counteract the damage of free radicals, and the free radical is a contributing factor to the aging and disease.When the liver is damage, such as suffering from all kinds of liver disease, the body will consume large amounts of GSH to help repair the injured liver and detoxification, that cause the body's glutathione are greatly reduced.But this time we need to take some glutathione peptide drugs, is advantageous to the injury of liver to repair itself.Thus, glutathione peptide drugs are suitable for viral hepatitis (hepatitis a and hepatitis b, etc.), alcoholic liver disease,drug-induced liver disease, fatty liver disease ,it’s a good medicine to protect liver.
Three active peptide compound
Glutathione (Glutathione, GSH) is made up of glutamic acid, cysteine and glycine by peptide bonds condensation of three peptide compounds, chemical name called gamma-L-glutamine-L-in ammonia acyl-glycine, its structural formula is shown in figure 1. Structured from the figure, the GSH and other peptide and protein is different, it's a special peptide bond in the molecule,by glutamate gamma carboxyl (-COOH) and alpha amino-cysteine (NH2) peptidebond condensation.
Figure 1 :Glutathione (GSH) chemical structural formula
GSH biosynthesis is directly controlled by its synthetase, rather than as protein synthesis is conducted on the ribosome, glutathione biosynthesis includes the following two reaction, as shown in figure 2.
Figure 2: The synthesis of GSH
Hopkins first discovered glutathione as early as 1921 , than divided it into reduced glutathione (GSH) and oxidative type (GSSG) two kinds.GSH exists in all living cells, it’s higher in yeast, wheat germ and liver, 100~1000 mg/100 g.According to recent data, S.c erevisiae Jacqueline Nottingham-5-8 strains of GSH content of up to 3058 mg/3058 g.In dry yeast type oxidation GSH exists, and almost all people in red blood cells were reduced glutathione, GSH can be synthesized in the red blood cells.Glutathione molecule contains a lively mercapto-SH, susceptible to oxidative dehydrogenation, two molecules of reduced glutathione (GSH) into a molecular dehydrogenation oxidation type glutathione (GSSG).Peptide by oxidation type in two three disulfide bond together, which play an important physiological role in living organisms is reduced glutathione, GSSG as GSH is physiological activity.
The physical and chemical properties
Glutathione molecular weight of 307.33, melting point of 189~193 ℃ (decomposition), crystal is colorless transparent thin cylindrical in shape and isoelectric point of 5.93.It is soluble in water, dilute alcohol, liquid ammonia and methyl formamide, and insoluble in alcohol, ether and acetone.Organisms only with physiological activity, GSH and GSSG need to restore to play its important physiological functions.The GSH under high water activity is not easy to save, only controlling the water activity below 0.3 to long-term stability.Studies have found that in vitamin C (pH3.3) in aqueous solution containing GSH, with strong reducing effect of vitamin C, GSH no oxidation of solution for the GSSG, but the decomposition speed is accelerated;But in the vitamin C solution GSSG will not change as GSH, and save the stability is very good.And oral intake of GSSG in the upper small intestine can be restored as GSH, in the small intestine epithelial cell surface by gamma GTP (GSH is decomposed into glutamic acid and Cys-Gly) and the role of the dipeptide enzyme and is absorbed, can also play an important physiological function.
Glutathione is widely found in animals and plants, and the contents of the bread yeast, wheat germ and animal liver are very high,100~100 mg/1000 g;Content is also rich in human and animal blood, such as human blood contains 26~34 mg/100 g, chicken blood contains 58-73 mg/73 g, pig blood contains 10~15 mg/100 g, the dog blood contains 14~22 mg/100 g.Many vegetables, potato and corn also contains GSH (see table 1).
The above information is edited bytongtong of lookchem.
Food additives
1. join the flour products, can play a role of reduction.Not only make the time of making bread reduced to half of the original or a third, labor conditions greatly improved, and a food nutrition reinforcement and other functions.
2. it added to the yogurt and infant foods, the equivalent of vitamin C, can have the effect of stabilizing agent.
3.to the fish cake, it can prevent the color deepened.
4.added to foods such as meat and cheese, with strong flavor of effect.
Foods rich in glutathione
Onions, garlic, tomato, fish, shrimp, lamb, peppers.
Reduced glutathione
Reduced glutathione (GSH) is a kind of important material in the cell, which is composed of glutamic acid, cysteine and glycine, containing sulphur, in order to maintain cell biological functions play an important role, has a variety of biological functions, including participation in the Krebs cycle and sugar metabolism,which is glyceraldehyde triose phosphate dehydrogenase and phosphoric acid dehydrogenase coenzyme, to activate a variety of enzymes, promote sugar, fat and protein metabolism, influence the process of cell metabolism;Through the thiol and free radicals in the body and the electronic base,than change into easy metabolic acids substances, accelerate the elimination of the free radicals, and avoid damage to the cell, reduce the toxic effects of chemotherapy, radiotherapy, protect the renal tubules from damage of cisplatinGSH can be used to protect the liver, the synthesis of the liver, the function of the toxin, and the toxin, promote the metabolism of bile acids, which is beneficial to the absorption of fat and fat soluble vitamins. Apply to alleviate chemotherapy, radiation therapy, especially the toxic effects of high-dose chemotherapy;Or for the treatment of all kinds of hypoxemia, such as acute anemia, acute respiratory distress syndrome, sepsis, etc.;It can be used for liver diseases, including viral, drugs, alcohol and other chemical toxicity caused by the treatment of liver damage.In addition reduced glutathione can also be used for organophosphorus, amino, or aid in the treatment of nitro aromatic compounds poisoning.For acute drug-induced renal injury, uremia, diabetes complications, and also have therapeutic effect of neuropathy.
Antidote
Glutathione has a broad spectrum of detoxification, which can enter the body with toxic compounds such as acrylonitrile, fluoride, carbon monoxide and heavy metal ions or carcinogens, combining and promote its eduction body outside, of these substances can be used for the treatment of the disease.
Antiallergic agent
The anti-allergic effect can treat the body acetylcholine, cholinesterase imbalances caused by allergies.
Protect liver agent
To protect the liver and inhibit the formation of fatty liver function, It not only can be used as a hepatoprotective agent, but also as a feed additive, it can protect the liver of fish and cattle.In aquaculture, because of too close breeding and unclean feed , often lead to liver dysfunction occurs in fishes and cows, adding glutathione can improve liver function.
GSH depletion
In the combination of glutathione and glutathione, the catalytic activity of glutathione-S-transferase and the combination of exogenous chemicals or their metabolites, which can decrease the toxicity and increase the polarity, is one of the most important methods in the biological transformation.When is suitable for the reaction of exogenous chemicals in large doses, may make the depletion of glutathione, a metabolic saturation (metabolic saturation), and in combined with the amount of time no longer increases with the increase of the exogenous chemicals dosage.The corresponding exogenous chemical toxicity, then the dose-response curve with a low dose not, the poison dynamics is characterized by nonlinear dynamics.GSH depletion mixed order is some kind of exogenous chemicals dosage is too large, also can be due to another foreign competition the combination effect of chemicals, or because of undernutrition or tissue damage that glutathione reduced supplies.GSH depletion have any condition that causes can make the original tolerance dose of poison.
Antioxidants
Many biochemical reactions in the human body are enzyme catalyzed reactions, most of these enzymes with thiol as active groups, the state of the thiol group determines the activation and inhibition of enzyme activity. Glutathione is natural activator, these enzymes in cells containing sulphur human body cell metabolism can be generated by H2O2 back into H2O, remove free radicals in the body.Free radicals can damage the cell membrane, promote the body's aging, and induce tumor or hardening of the arteries.Of anti peroxidation to human cells, but also can improve the antioxidant ability of skin, make skin burnish.Human aging, infections, poisoning, exogenous toxins, oxidative stress, electrophilic compound attack can be made within the cell plasma GSH level reduces, the phenomenon of apoptosis occurs in very early stage, its degradation process can be observed in the early apoptosis, so it can be observed in the early stage of apoptosis.
Glutathione can eliminate lipid oxidation generating , and has the oxidation resistance to grease, still can prevent the sapidity nucleotide (inosinic acid, guanylic acid) food (fish cake, sausage, soy sauce, etc.) of the nucleotide decomposition and lose taste delicious taste.
The preparation of GSH
Since 1938, the first patent for the use of yeast GSH has been published, and a large number of patent applications have since been published.In general, the preparation methods of GSH are solvent extraction, enzymatic, fermentation and chemical synthesis of four.At present, mainly from the cultivation of high content GSH yeast extract, domestic manufacturers have Shanghai yeast plant and a number of institutions, research units are being developed, foreign manufacturers are BDH, Fluka, J.T.Baker, E.Merck, Haen Riedel-de, Siqma and Japan and the light of the public.The extraction method and enzyme method are mostly wheat germ as raw material, by adding appropriate solvent or combined with amylase, protease treatment, and then by centrifugal, separation and purification. The process flow is simple, see figure 4.
Figure 4:The technological process of extraction of glutathione from wheat germ
By biotechnology means preparation of glutathione in two ways, one is the selection of high-yielding yeast strains that are rich in GSH, and through the separation system, figure 5 shows a simple technological process.Another way is by cultivating algae that are rich in GSH, extraction is similar to the yeast extract method.
Figure 5: The technological process of extraction of glutathione from yeast cell
Originator
L-Glutathione,Solgar,USA
Manufacturing Process
The tripeptide thiol glutathione (L-γ-glutamyl-L-cysteinyl-glycine (GSH)) found
in virtually all cells functions in metabolism, transport and cellular protection.
Glutathione may be obtained from an yeast or synthetically.
A yeast containing 600 parts of yeast solids is heated just to the boiling point
of water. The yeast solids are removed by centrifuging or filtration. Sulphuric
acid is added to the filtrate to give 0.5 N strength as sulphuric acid 6 parts of
ascorbic acid are added. Then 2 parts of cuprous oxide are added with
stirring. The reaction mixture is then centrifuged and washed until the
precipitate is free from sulphates. The precipitate is suspended in 100 parts of
water and hydrogen sulfide is bubbled through the water until all of the
copper is precipitated as copper sulphide. The filtrate is evaporated and the
glutathione is purified by recrystallization from 50% ethanol. All parts are by
weight.
The preparation of glutathion by methods of peptide synthesis is expansive
and gives 20-30% yield of GHS. For the first time synthetic glutathion was
prepared by M. Bergmann et al.
Therapeutic Function
Anabolic, Antidote
benefits
Glutathione contentin human blood is 26～34mg/100g,scavenging free radical, anti-oxidant, whiteningand spot-removing.Its recommended dosage in skin care products is 0.5~2%.
Biochem/physiol Actions
Endogenous antioxidant that plays a major role in reducing reactive oxygen species formed during cellular metabolism and the respiratory burst. Glutathione-S-transferase catalyzes the formation of glutathione thioethers with xenobiotics, leukotrienes, and other molecules that have an electrophilic center. Glutathione also forms disulfide bonds with cysteine residues in proteins. Via these mechanisms, it can have the paradoxical effect of reducing the efficacy of anti-cancer agents.
Safety Profile
Moderately toxic by
intravenous route. Experimental
reproductive effects. Human mutation data
reported. When heated to decomposition it
emits very toxic fumes of SOx and NOx.
Purification Methods
Crystallise L-glutathione from 50% aqueous EtOH, dry it in a vacuum and
Check Digit Verification of cas no
The CAS Registry Mumber 70-18-8 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 7 and 0 respectively; the second part has 2 digits, 1 and 8 respectively.
Calculate Digit Verification of CAS Registry Number 70-18:
(4*7)+(3*0)+(2*1)+(1*8)=38
38 % 10 = 8
So 70-18-8 is a valid CAS Registry Number.
InChI:InChI=1/C10H17N3O6S/c11-5(1-2-7(14)15)9(18)13-6(4-20)10(19)12-3-8(16)17/h5-6,20H,1-4,11H2,(H,12,19)(H,13,18)(H,14,15)(H,16,17)
70-18-8Relevant articles and documents
Fraenkel-Conrat
, p. 2534 (1941)
Synthesis of novel chiral bis-N-substituted-hydrazinecarboxamide receptors and probing their solution-phase recognition to chiral carboxylic guests by ESI-TOF/MS and tandem ESI-MS
Nour, Hany F.,Golon, Agnieszka,Islam, Tuhidul,Fernández-Lahore, Marcelo,Kuhnert, Nikolai
, p. 11130 - 11137 (2013)
Seven novel bis-N-substituted-hydrazinecarboxamide receptors were synthesized in good to excellent yields by reacting chiral dicarbohydrazides, obtained from commercially available tartaric acid, with substituted aromatic isocyanates. The newly synthesized hydrazinecarboxamides formed structurally unique supramolecular aggregates, which have been confirmed by ESI-TOF/MS and tandem ESI-MS. They also showed molecular recognition to a selection of chiral carboxylic guests and oligopeptides, which mimic the backbone structure of the bacterial cell wall. The structures of the novel compounds were verified by various spectroscopic techniques including FTIR, 1H NMR, 13C NMR, ESI-TOF/MS, tandem ESI-MS, 2D ROESY NMR, and CD spectroscopy.
Dissecting the catalytic mechanism of trypanosoma brucei trypanothione synthetase by kinetic analysis and computational modeling
Leroux, Alejandro E.,Haanstra, Jurgen R.,Bakker, Barbara M.,Krauth-Siegel, R. Luise
, p. 23751 - 23764 (2013)
Background: Trypanothione synthetase catalyzes the conjugation of spermidine with two GSH molecules to form trypanothione. Results: The kinetic parameters were measured under in vivo-like conditions. A mathematical model was developed describing the entire kinetic profile. Conclusion: Trypanothione synthetase is affected by substrate and product inhibition. Significance: The combined kinetic and modeling approaches provided a so far unprecedented insight in the mechanism of this parasite-specific enzyme.
Millisecond dynamics in glutaredoxin during catalytic turnover is dependent on substrate binding and absent in the resting states
Jensen, Kristine Steen,Winther, Jakob R.,Teilum, Kaare
, p. 3034 - 3042 (2011)
Conformational dynamics is important for enzyme function. Which motions of enzymes determine catalytic efficiency and whether the same motions are important for all enzymes, however, are not well understood. Here we address conformational dynamics in glutaredoxin during catalytic turnover with a combination of NMR magnetization transfer, R2 relaxation dispersion, and ligand titration experiments. Glutaredoxins catalyze a glutathione exchange reaction, forming a stable glutathinoylated enzyme intermediate. The equilibrium between the reduced state and the glutathionylated state was biochemically tuned to exchange on the millisecond time scale. The conformational changes of the protein backbone during catalysis were followed by 15N nuclear spin relaxation dispersion experiments. A conformational transition that is well described by a two-state process with an exchange rate corresponding to the glutathione exchange rate was observed for 23 residues. Binding of reduced glutathione resulted in competitive inhibition of the reduced enzyme having kinetics similar to that of the reaction. This observation couples the motions observed during catalysis directly to substrate binding. Backbone motions on the time scale of catalytic turnover were not observed for the enzyme in the resting states, implying that alternative conformers do not accumulate to significant concentrations. These results infer that the turnover rate in glutaredoxin is governed by formation of a productive enzyme-substrate encounter complex, and that catalysis proceeds by an induced fit mechanism rather than by conformer selection driven by intrinsic conformational dynamics.
A New Synthesis of Glutathione via the Thiazoline Peptide
Ozawa, Yoichi,Tsuji, Toshiaki,Ariyoshi, Yasuo
, p. 2592 - 2593 (1980)
A convenient synthesis of glutathione (GSH) by the use of minimal protecting groups was investigated.N-Formyl-L-2-amino-4-cyanobutyric acid ethyl ester was condensed with ethyl L-cysteinylglycinate to give (4R)-2--4-(ethoxycarbonylmethylcarbamoyl)-2-thiazoline.This compound was saponified in aqueous acetone at -15- -20 deg C and subsequently treated with dilute H2SO4 (pH 4) to yield formylglutathione, whose formyl group was then hydrolyzed with 0.5 M (1M = 1 mol dm-3) H2SO4 to give free GSH.For purification, this was changed to a copper thiolate, which was then decomposed with H2S to afford pure GSH.
Acetone/Isopropanol Photoinitiating System Enables Tunable Disulfide Reduction and Disulfide Mapping via Tandem Mass Spectrometry
Adhikari, Sarju,Yang, Xiaoyue,Xia, Yu
, p. 13036 - 13043 (2018)
Herein, we report the development of a new photochemical system which enables rapid and tunable disulfide bond reduction and its application in disulfide mapping via online coupling with mass spectrometry (MS). Acetone, a clean and electrospray ionization (ESI) compatible solvent, is used as the photoinitiator (1% volume) in the solvent system consisting of 1:1 alkyl alcohol and water. Under ultraviolet (UV) irradiation (～254 nm), the acetone/alcohol system produces hydroxyalkyl radicals, which are responsible for disulfide bond cleavage in peptides. Acetone/isopropanol is most suitable for optimizing the disulfide reduction products, leading to almost complete conversion in less than 5 s when the reaction is conducted in a flow microreactor. The flow microreactor device not only facilitates direct coupling with ESI-MS but also allows fine-tuning of the extent of disulfide reduction by varying the UV exposure time. Near full sequence coverage for peptides consisting of intra- or interchain disulfide bonds has been achieved from complete disulfide reduction and online tandem mass spectrometry (MS/MS) via low energy collision-induced dissociation. Coupling different degrees of partial disulfide reduction with ESI-MS/MS allows disulfide mapping as demonstrated for characterizing the three disulfide bonds in insulin.
Structural and biochemical analyses indicate that a bacterial persulfide dioxygenase-rhodanese fusion protein functions in sulfur assimilation
Motl, Nicole,Skiba, Meredith A.,Kabil, Omer,Smith, Janet L.,Banerjee, Ruma
, p. 14026 - 14038 (2017)
Hydrogen sulfide (H2S) is a signaling molecule that is toxic at elevated concentrations. In eukaryotes, it is cleared via a mitochondrial sulfide oxidation pathway, which comprises sulfide quinone oxidoreductase, persulfide dioxygenase (PDO), rhodanese, and sulfite oxidase and converts H2S to thiosulfate and sulfate. Natural fusions between the non-heme iron containing PDOand rhodanese, a thiol sulfurtransferase, exist in some bacteria. However, little is known about the role of the PDO-rhodanese fusion (PRF) proteins in sulfur metabolism. Herein,we report the kinetic properties and the crystal structure of a PRF from the Gram-negative endophytic bacterium Burkholderia phytofirmans. The crystal structures of wild-type PRF and a sulfurtransferase-inactivated C314S mutant with and without glutathione were determined at 1.8, 2.4, and 2.7 ? resolution, respectively. We found that the two active sites are distant and do not show evidence of direct communication. The B. phytofirmans PRF exhibited robust PDO activity and preferentially catalyzed sulfur transfer in the direction of thiosulfate to sulfite and glutathione persulfide; sulfur transfer in the reverse direction was detectable only under limited turnover conditions. Together with the kinetic data, our bioinformatics analysis reveals that B. phytofirmans PRF is poised to metabolize thiosulfate to sulfite in a sulfur assimilation pathway rather than in sulfide stress response as seen, for example, with the Staphylococcus aureus PRF or sulfide oxidation and disposal as observed with the homologous mammalian proteins.
Theoretical and Experimental Investigation of Thermodynamics and Kinetics of Thiol-Michael Addition Reactions: A Case Study of Reversible Fluorescent Probes for Glutathione Imaging in Single Cells
Chen, Jianwei,Jiang, Xiqian,Carroll, Shaina L.,Huang, Jia,Wang, Jin
, p. 5978 - 5981 (2015)
Density functional theory (DFT) was applied to study the thermodynamics and kinetics of reversible thiol-Michael addition reactions. M06-2X/6-31G(d) with the SMD solvation model can reliably predict the Gibbs free energy changes (ΔG) of thiol-Michael addition reactions with an error of less than 1 kcal·mol-1 compared with the experimental benchmarks. Taking advantage of this computational model, the first reversible reaction-based fluorescent probe was developed that can monitor the changes in glutathione levels in single living cells.
Reaction of COTC with glutathione: Structure of the putative glyoxalase I inhibitor
Huntley, C. Frederick M.,Hamilton, Diana S.,Creighton, Donald J.,Ganem, Bruce
, p. 3143 - 3144 (2000)
(matrix presented) The structure of the active glyoxalase I inhibitor derived from the Streptomyces griseosporeus metabolite COTC 1 has been conclusively identified by means of total synthesis as 2c. Human glyoxalase I is competitively inhibited by 2c (Ki = 183 ± 6 μM) but is not inhibited by 1 itself.
A promiscuous glutathione transferase transformed into a selective thiolester hydrolase
Hederos, Sofia,Tegler, Lotta,Carlsson, Jonas,Persson, Bengt,Viljanen, Johan,Broo, Kerstin S.
, p. 90 - 97 (2006)
Human glutathione transferase A1-1 (hGST A1-1) can be reengineered by rational design into a catalyst for thiolester hydrolysis with a catalytic proficiency of 1.4 × 107 M-1. The thiolester hydrolase, A216H that was obtained by the introduction of a single histidine residue at position 216 catalyzed the hydrolysis of a substrate termed GSB, a thiolester of glutathione and benzoic acid. Here we investigate the substrate requirements of this designed enzyme by screening a thiolester library. We found that only two thiolesters out of 18 were substrates for A216H. The A216H-catalyzed hydrolysis of GS-2 (thiolester of glutathione and naphthalenecarboxylic acid) exhibits a kcat of 0.0032 min -1 and a KM of 41 M. The previously reported catalysis of GSB has a kcat of 0.00078 min-1 and KM of 5 M. The kcat for A216H-catalyzed hydrolysis of GS-2 is thus 4.1 times higher than for GSB. The catalytic proficiency (kcat/K M)/kuncat for GS-2 is 3 × 106 M -1. The promiscuous feature of the wt protein towards a range of different substrates has not been conserved in A216H but we have obtained a selective enzyme with high demands on the substrate. The Royal Society of Chemistry 2006.
Electrical 'Wiring' of Glutathione Reductase: an Efficient Method for the Reduction of Glutathione using Molecular Hydrogen as the Reductant
Willner, Itamar,Lapidot, Noa
, p. 617 - 618 (1991)
The enzyme glutathione reductase is chemically modified to become electrically conductive, thus facilitating the reduction of oxidized glutathione to its reduced form using hydrogen as the reductant, and the modified enzyme and Pt colloid as catalysts.
Metal-dependent inhibition of glyoxalase II: A possible mechanism to regulate the enzyme activity
Campos-Bermudez, Valeria A.,Morán-Barrio, Jorgelina,Costa-Filho, Antonio J.,Vila, Alejandro J.
, p. 726 - 731 (2010)
Glyoxalase II (GLX2, EC 3.1.2.6., hydroxyacylglutathione hydrolase) is a metalloenzyme involved in crucial detoxification pathways. Different studies have failed in identifying the native metal ion of this enzyme, which is expressed with iron, zinc and/or manganese. Here we report that GloB, the GLX2 from Salmonella typhimurium, is differentially inhibited by glutathione (a reaction product) depending on the bound metal ion, and we provide a structural model for this inhibition mode. This metal-dependent inhibition was shown to occur in metal-enriched forms of the enzyme, complementing the spectroscopic data. Based on the high levels of free glutathione in the cell, we suggest that the expression of the different metal forms of GLX2 during Salmonella infection could be exploited as a mechanism to regulate the enzyme activity.
Visible Light-Mediated Synthesis of Se?S Bond-Containing Peptides
Arsenyan, Pavel,Dimitrijevs, Pavels,Lapcinska, Sindija
supporting information, p. 3968 - 3972 (2021/07/26)
A visible light-initiated method has been developed for preparation of Se?S bond-containing peptides. The method is based on generation of sulfur-centered radical employing organic dye. The protocol is tolerant to unprotected peptides with “sensitive” amino acids. The stability of Se?S bond is evaluated in buffers at different pH (3.0–10.0) and also in the presence of oxidants and reducing agents. Additionally, the ability of Se?S bond to serve as an oxidation sensitive linker in biocompatible materials has been confirmed. (Figure presented.).
Crystal-facet-dependent denitrosylation: Modulation of NO release from S-nitrosothiols by Cu2O polymorphs
Ghosh, Sourav,Roy, Punarbasu,Prasad, Sanjay,Mugesh, Govindasamy
, p. 5308 - 5318 (2019/05/29)
Nitric oxide (NO), a gaseous small molecule generated by the nitric oxide synthase (NOS) enzymes, plays key roles in signal transduction. The thiol groups present in many proteins and small molecules undergo nitrosylation to form the corresponding S-nitrosothiols. The release of NO from S-nitrosothiols is a key strategy to maintain the NO levels in biological systems. However, the controlled release of NO from the nitrosylated compounds at physiological pH remains a challenge. In this paper, we describe the synthesis and NO releasing ability of Cu2O nanomaterials and provide the first experimental evidence that the nanocrystals having different crystal facets within the same crystal system exhibit different activities toward S-nitrosothiols. We used various imaging techniques and time-dependent spectroscopic measurements to understand the nature of catalytically active species involved in the surface reactions. The denitrosylation reactions by Cu2O can be carried out multiple times without affecting the catalytic activity.
