3081-62-7Relevant articles and documents
Antidiabetic activity of Zn(II) complexes with a derivative of L-glutamine
Matsumoto, Kinuyo,Yamamoto, Shuhei,Yoshikawa, Yutaka,Doe, Matsumi,Kojima, Yoshitane,Sakurai, Hiromu,Hashimoto, Hiroko,Kajiwara, Naemi M.
, p. 1077 - 1081 (2005)
The insulinomimetic activity of zinc(II) complexes Zn(gln-m)2 and Zn(gln-e)2, respectively, with L-γ-glutamyl-methylamide (gln-m) and -ethylamide (theanine: gln-e), components of green tea, were compared to that of Zn(gln)2 with L-glutamine (gin) in an in vitro study using isolated rodent adipocytes treated with epinephrine in the presence of glucose, expressed as the IC50 value (50% inhibition concentration) of free fatty acids (FFA) released from fat cells. The former were found to have higher inslinomimetic activity than that of the latter. The IC50 values of the former were 0.61 and 0.56, respectively. Then, the anti-diabetic activity of a zinc(II) complex, Zn(gln-e)2, was examined in an in vivo experiment on KK-Aγ mice, model animals of type-2 DM, by the intraperitoneal (ip) injection of 3-4 mg Zn/kg b.w./day for 13 days. The blood-glucose level of a group treated with a Zn complex, Zn(gln-e)2, decreased significantly after 13 days compared to those of non-treated and gln-e treated groups. The serum concentrations of triglyceride (TG) and HbA1C decreased significantly in Zn(gln-e) 2 treated KK-Aγ mice compared to those of the gln-e treated group, respectively. Furthermore, the improvement in glucose tolerance was confirmed by an oral glucose tolerance test.
Tasiamide F, a potent inhibitor of cathepsins D and E from a marine cyanobacterium
Al-Awadhi, Fatma H.,Ratnayake, Ranjala,Paul, Valerie J.,Luesch, Hendrik
, p. 3276 - 3282 (2016/07/21)
In search of novel protease inhibitors with therapeutic potential, our efforts exploring the marine cyanobacterium Lyngbya sp. have led to the discovery of tasiamide F (1), which is an analogue of tasiamide B (2). The structure was elucidated using a combination of NMR spectroscopy and mass spectrometry. The key structural feature in 1 is the presence of the Phe-derived statine core, which contributes to its aspartic protease inhibitory activity. The antiproteolytic activity of 1 and 2 was evaluated in vitro against cathepsins D and E, and BACE1. Tasiamide F (1) displayed IC50values of 57?nM, 23?nM, and 0.69?μM, respectively, indicating greater selectivity for cathepsins over BACE1 compared with tasiamide B (2). Molecular docking experiments were carried out for compounds 1 and 2 against cathepsins D and E to rationalize their activity towards these proteases. The dysregulated activities of cathepsins D and E have been implicated in cancer and modulation of immune responses, respectively, and these proteases represent potential therapeutic targets.
Peptide Tyrosinase Activators
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, (2015/06/10)
Peptides that increase melanin synthesis are provided. These peptides include pentapeptides YSSWY, YRSRK, and their variants. The peptides may activate the enzymatic activity of tyrosinase to increase melanin synthesis. The pharmaceutical, cosmetic, and other compositions including the peptides are also provided. The methods of increasing melanin production in epidermis of a subject are provided where the methods include administering compositions comprising an amount of one or more peptides effective to increase the melanin production. The methods also include treating vitiligo or other hypopigmentation disorders with compositions including one or more peptides.
Molecular cloning and characterization of γ-Glutamyltranspeptidase from pseudomonas nitroreducens IFO12694
Imaoka, Masashi,Yano, Shigekazu,Okumura, Masashi,Hibi, Takao,Wakayama, Mamoru
, p. 1936 - 1939 (2011/06/11)
y-Glutamyltranspeptidase from Pseudomonas nitroreducens IFO12694 (PnGGT) exhibited higher hydro-lytic activity than transfer activity, as compared with other y-glutamyltranspeptidases (GGTs). PnGGT showed little activity towards most of L-amino acids and towards glycyl-glycine, which is often used as a standard y-glutamyl accepter in GGT transfer reactions. The preferred substrates for PnGGT as a y-glutamyl accepter were amines such as methylamine, ethylamine, and isopropylamine.
A novel catalytic ability of γ-glutamylcysteine synthetase of Escherichia coli and its application in theanine production
Miyake, Koichiro,Kakita, Shingo
experimental part, p. 2677 - 2683 (2010/09/11)
γ-Glutamylcysteine synthetase (γGCS, EC 6.3.2.2) catalyzes the formation of γ-glutamylcysteine from L-glutamic acid (Glu) and L-cysteine (Cys) in an ATP-dependent manner. While γGCS can use various amino acids as substrate, little is known about whether it can use non-amino acid compounds in place of Cys. We determined that γGCS from Escherichia coli has the ability to combine Glu and amines to form γ-glutamylamides. The reaction rate depended on the length of the methylene chain of the amines in the following order: n-propylamine > butylamine > ethylamine methylamine. The optimal pH for the reaction was narrower and more alkaline than for the reaction with an amino acid. The newly found catalytic ability of γGCS was used in the production of theanine (γ-glutamylethylamine). The resting cells of E. coli expressing γGCS, in which ATP was regenerated through glycolysis, synthesized 12.1 mm theanine (18 h) from 429 mm ethylamine.
Characterization of theanine-forming enzyme from Methylovorus mays No. 9 in respect to utilization of theanine production
Yamamoto, Sachiko,Wakayama, Mamoru,Tachiki, Takashi
, p. 545 - 552 (2008/03/27)
For development of theanine production from glutamic acid and ethylamine by coupling yeast sugar fermentation as an ATP-regenerating system, several strains were selected from among about 200 methylamine- and/or methanol-assimilating bacteria depending on the theanine-forming activity of their permeated cells. The amount of theanine formed by the cells of the selected strains was much larger than that by the cells of Escherichia coli AD494 (DE3) expressing Pseudomonas taetrolens Y-30 glutamine synthetase (GS), which has been found to be a usable enzyme for theanine production. A GS-like enzyme responsible for the theanine-forming reaction was obtained from an obligate methylotroph isolate, Methylovorus mays No. 9. The enzyme was induced by methylamine in the culture medium. A molecular mass of 410-470 kDa was obtained by gel filtration of the enzyme, and 51 kDa by SDS-PAGE analysis. The enzyme showed high activity toward methylamine rather than ammonia, which indicates that it is similar to known γ-glutamylmethylamide synthetase. The isolated enzyme also had high reactivity to ethylamine in a neutral pH range, and formed theanine from glutamic acid and ethylamine in a reaction mixture containing a yeast sugar fermentation system for ATP-regeneration.
Purification and characterization of glutamine synthetase of Pseudomonas taetrolens Y-30: An enzyme usable for production of theanine by coupling with the alcoholic fermentation system of baker's yeast
Yamamoto, Sachiko,Uchimura, Kousuke,Wakayama, Mamoru,Tachiki, Takashi
, p. 1888 - 1897 (2007/10/03)
Concentrated cell-extract of Pseudomonas taetrolens Y-30, isolated as a methylamine-assimilating organism, formed γ-glutamylethylamide (theanine) from glutamic acid and ethylamine in a mixture containing the alcoholic fermentation system of baker's yeast for ATP-regeneration. Glutamine synthetase (GS), probably responsible for theanine formation, was isolated from the extract of the organism grown on a medium containing 1% methylamine, 1% glycerol, 0.5% yeast extract, and 0.2% polypepton as carbon and nitrogen sources. The molecular mass was estimated to be 660 kDa by gel filtration and 55 kDa by SDS-polyacrylamide gel electrophoresis, suggesting that Ps. taetrolens Y-30 GS consists of 12 identical subunits. The enzyme required Mg2+ or Mn2+ for its activity. Under the standard reaction condition for glutamine formation (pH 8.0 with 3o mM Mg2+), GS showed 7% and 1% reactivity toward methylamine and ethylamine respectively of that to ammonia. Reactivity to the alkylamines varied with optimum pH of the reaction in response to divalent cation in the mixture: pH 11.0 was the optimum for the Mg 2+-dependent reaction with ethylamine, and pH 8.5 was the optimum for the Mn2+-dependent reaction. In a mixture of an optimum reaction condition with 1000 mM ethylamine (at pH 8.5 with 3 mM Mn2+), reactivity increased up to 7% of the reactivity to ammonia in the standard reaction condition. The isolated GS formed theanine in the mixture with the yeast fermentation system.
γ-Glutamyl Transfer Reactions by Glutaminase from Pseudomonas nitroreducens IFO 12694 and Their Application for the Syntheses of Theanine and γ-Glutamylmethylamide
Tachiki, Takashi,Yamada, Takeshi,Mizuno, Katsushige,Ueda, Masashi,Shiode, Ju-Ichi,Fukami, Hiroshi
, p. 1279 - 1283 (2007/10/03)
In a mixture containing γ-glutamyl donor (donor) and γ-glutamyl acceptor (acceptor), the glutaminase of Pseudomonas nitroreducens IFO 12694 simultaneously catalyzed a γ-glutamyl transfer reaction and hydrolysis of the donor. The variation of the activities responding to the concentration of glutathione and glycylglycine indicated that the enzyme might be classified in a group of glutaminases that shows hydrolysis prior to transfer reaction. On the other hand, the results with glutamine and ethylamine or methylamine indicated that the enzyme was active in the transfer reaction with suppressed hydrolysis of glutamine, and suggested the possibility of using the reaction for producing γ-glutamylethylamide (theanine) or γ-glutamylmethylamide (γ-GMA). In fact, in a mixture containing high concentrations of substrates (0.7 M glutamine, 1.5 M ethylamine or methylamine) and 0.5 unit/ml glutaminase (borate buffer pH 11), 270 mM (47 g/L) theanine or 250 mM (38 g/L) γ-GMA was formed in 7 h of incubation at 30°C.
Purification and Characterization of γ-Glutamylmethylamide Synthetase from Methylophaga sp. AA-30
Kimura, Toshio,Sugahara, Isao,Hanai, Katsuyuki,Tonomura, Yuuko
, p. 708 - 711 (2007/10/02)
γ-Glutamylmethylamide synthetase was purified about 70-fold from a cell-free extract of Methylophaga sp.AA-30 by ammonium sulfate fractionation, Octyl-Sepharose column chromatography, and Sephacryl S-300 gel filtration.Only a single protein band was detected after SDS-polyacrylamide gel electrophoresis of the purified preparation; the band was at a position corresponding to a molecular weight of 56,000.The molecular weight of the enzyme was calculated to be 440,000 by Superose 6HR gel filtration, so we suggest that the enzyme is an octomer of identical subunits.The enzyme had maximum activity at pH 7.5 and 40 deg C.It could use ethylamine and propylamine instead of methylamine as the substrate, but it could not use D-glutamate or L-glutamine instead of L-glutamate.
