• Bulletin of the Korean Chemical Society
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• 제17권5호
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• pp.466-468
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• 1996

• BMB Reports
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• 제32권6호
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• pp.547-553
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• 1999

Aminoacyl-tRNA synthetases are essential enzymes catalyzing the attachment of specific amino acids to cognate tRNAs. In the present work, the substrate analogue L-methionine hydroxamate was used to identify functional residues located in the active site of the E. coli methionyl-tRNA synthetase (MetRS). This compound inhibited bacteria, yeast, and human MetRS activities to a similar degree, suggesting a conserved active site structure and mechanism between MetRSs of different phylogenetic domains. Mutants of the E. coli MetRS resistant to methionine hydroxamate were also isolated. These mutants contained a substitution either at T10, Y15, or Y94. These residues are highly conserved among the different MetRSs and the mutants showed decreased aminoacylation activity, suggesting their functional and structural significances. The putative roles of these residues are discussed on a structural basis.

• 한국미생물·생명공학회지
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• 제23권1호
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• pp.81-86
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• 1995

A Streptomyces strain YS-943, which produced amino acid antimetabolite, was isolated from soil. During the course of screening for new amino acid antimetabolites from the culture broth of Actinomycetes, we found that the strain produced a substance active against Gram-positive bacteria and its activity was reversed by L-methionine and L-histidine on the synthetic minimal agar medium in the culture broth.The morphological and cultural characteristics serve to identify the producing organism strain YS-943 as the genus Streptomyces. Fermentation was carried out in the synthetic medium at 28$\CIRC$C for 48 hours. The fermentation yield reached about 12 mg per liter of the broth. The YS-943 substance was obtained as white powder, mp 194$\CIRC$C and has the molecular formular of C$_{4}$H$_{8}$N$_{2}$O$_{4}$. Its structure was determined to be o-carbamyl-D-serine by spectroscopic data. It is active against some Gram-positive bacteria and reversed by L-methionine and L-histidine.

• Asian-Australasian Journal of Animal Sciences
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• 제24권7호
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• pp.974-981
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• 2011

This study was designed to re-evaluate the dietary methionine requirement by means of the plasma methionine and ammonia concentrations in surgically modified rainbow trout, Oncorhynchus mykiss. A total of 35 rainbow trout averaging $505{\pm}6.5$ g (initial body weight, mean${\pm}$SD) were randomly distributed into seven groups with five fish in each group. After 48 h of feed deprivation, each group of fish was fed one of seven L-amino acid based diets containing 0.5% cystine and graded levels of methionine (0.25, 0.40, 0.50, 0.60, 0.70, 0.80 or 0.95% of diet, dry matter bases) by intubation at 1% body weight on dry matter basis. Blood samples were taken at 0, 5 and 24 h after intubation. Post-prandial plasma free methionine concentrations (PPmet, 5 h after intubation) and post-absorptive plasma free methionine concentrations (PAmet, 24 h after intubation) of fish fed diets containing 0.60% or higher methionine were significantly (p<0.05) higher than those of fish fed diets containing 0.50% or lower methionine. PPmet and PAmet in fish fed diets containing 0.60% or higher methionine were not significantly different except PPmet of fish fed diet containing 0.95% methionine. Post-prandial plasma ammonia concentrations (PPA, 5 h after intubation) of fish fed diets containing 0.70% or higher methionine were significantly higher than those of fish fed diets containing 0.60% or lower methionine, and PPA of fish fed diets containing 0.25 and up to 0.60% methionine were not significantly different from each other. Broken-line model analyses on PPmet, PAmet, and PPA indicated that the dietary methionine requirement of rainbow trout was between 0.59 (1.69) and 0.67 (1.91) % of diets (% dietary protein bases) when the diets contained 0.5% cystine.

• Nutrition Research and Practice
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• 제16권6호
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• pp.729-744
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• 2022

BACKGROUND/OBJECTIVES: 4-Hydroxy-2-nonenal (HNE) is a biomarker for oxidative stress to induce inflammation. Methionine is an essential sulfur-containing amino acid with antioxidative activity. On the other hand, the evidence on whether and how methionine can depress HNE-derived inflammation is lacking. In particular, the link between the regulation of the nuclear factor-κB (NF-κB) signaling pathway and methionine intake is unclear. This study examined the link between depression from HNE accumulation and the anti-inflammatory function of ⳑ-methionine in rats. MATERIALS/METHODS: Male Wistar rats (3-week-old, weighing 70-80 g) were administered different levels of ⳑ-methionine orally at 215.0, 268.8, 322.5, and 430.0 mg/kg body weight for two weeks. The control group was fed commercial pellets. The hepatic HNE contents and the protein expression and mRNA levels of the inflammatory mediators were measured. The interleukin-10 (IL-10) and glutathione S-transferase (GST) levels were also estimated. RESULTS: Compared to the control group, hepatic HNE levels were reduced significantly in all groups fed ⳑ-methionine, which were attributed to the stimulation of GST by ⳑ-methionine. With decreasing HNE levels, ⳑ-methionine inhibited the activation of NF-κB by up-regulating inhibitory κBα and depressing phosphoinositide 3 kinase/protein kinase B. The mRNA levels of the inflammatory mediators (cyclooxygenase-2, interleukin-1β, interleukin-6, inducible nitric oxide synthase, tumor necrotic factor alpha) were decreased significantly by ⳑ-methionine. In contrast, the protein expression of these inflammatory mediators was effectively down regulated by ⳑ-methionine. The anti-inflammatory action of ⳑ-methionine was also reflected by the up-regulation of IL-10. CONCLUSIONS: This study revealed a link between the inhibition of HNE accumulation and the depression of inflammation in growing rats, which was attributed to ⳑ-methionine availability. The anti-inflammatory mechanism exerted by ⳑ-methionine was to inhibit NF-κB activation and to up-regulate GST.

• 한국작물학회지
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• 제30권2호
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• pp.184-189
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• 1985

질소수준이 높아짐에 따라서 벼 엽신에서 에칠렌 생성량이 감소하는 원인에 대하여 에칠렌생합성계에 존재하는 전구물질 메치오닌 및 직접전구물질 ACC등을 벼에 처리하여 에칠렌생성량에 미치는 영향을 검토한 결과를 요약하면 다음과 같다. 1. 벼 유묘 및 엽에 메치오닌을 처리하면 처리농도가 높을수록 에칠렌생성량은 증가하였다. 2. 직접전구물질인 ACC를 엽신에 처리하면 처리농도가 높을수록 에칠렌생성량은 직선적으로 증가하였다. 3. 질소수준이 다를 벼의 유묘 및 엽신에 메치오닌 및 ACC를 처리하면 에칠렌생성량은 증가하나 질소수준이 높아질수록 에칠렌생성량은 현저히 억제 되어진다.

• 한국축산식품학회지
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• 제34권1호
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• pp.65-72
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• 2014

This study is executed to develop probiotics which produce S-adenosyl-L-methionine (SAM), a methyl group donor of the 5-methyltetrahydrofolate methylation reaction within the animal cell. SAM is an essential substance for the synthesis, activation, and metabolism of hormones, neurotransmitters, nucleic acids, phospholipids, and cell membranes of animals. The SAM is also known as a nutritional supplement to improve brain functions of the human. In this study, the SAM-producing strains are identified in 18 types of salted fish, and then, the strains with excellent SAM productions are being identified, with 1 strain in the Enterococcus genus and 9 strains in the Bacillus genus. Strains with a large amount of SAM production include the lactic acid bacteria such as En. faecium and En. durans, En. sanguinicola, as well as various strains in the Bacillus genus. The SAM-overproducing strains show antibacterial activities with certain harmful microbes in addition to the weak acid resistances and strong bile resistances, indicating characteristics of probiotics. It is possible that the jeotgal-originated beneficial strains with overproducing SAM can be commercially utilized in order to manufacture SAM enriched foods.

• 한국초지조사료학회지
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• 제10권3호
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• pp.141-146
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• 1990

Changes in dry matter yield, crude components, nutrients uptake($P_2O_5$, $K_2O$, CaO, MgO) and sulphur containing amino acid(cysteine, methionine) of orchardgrass(Dacty1is glomerata. L) and alfalfa(A4edicago sativa. L) by gypsum application(as sulphur source, 0, 2. 5, 10, 20kg SIlOa) were investigated to understand the effect of sulphur on herbage production in pasture, which was established in 1987 as means of hand broadcasting. The effect of gypsum on dry matter yield at different cutting times during growing seasons has not been found both in orchardgrass and in alfalfa, but in respect to annual total dry matter yield there were increment in herbage yield (P<0.05) of alfalfa at 5, 10, 20kg SIlOa in 1989 and the amounts of sulphur taken up in herbage slightly increased according to the rates of gypsum application. Maximum apparent recovery of sulphur was 7.55% at 2kg SIlOa in orchardgrass and was 17.8% at 5kg S/lOa in alfalfa. There were no any great differences in the content of crude components of both species and this trend was similar with the mineral contents of orchardgrass. But in alfalfa, the amounts of $K_2O$, CaO, and $P_2O_5$ taken up were increased by gypsum application and the increment in the amounts of minerals taken up in herbage at 20kg SIlOa were 14.9 of $K_2O$, 9.1 of CaO, and 2.5kgIlOa of $P_2O_5$ as compared to those of at untreated plot. Cysteine and methionine were not influenced by gypsum applicaton not only in orchardgrass but also cysteine in alfalfa, however, the content of methionine in alfalfa was slightly increased at 2, 5, lOkg SIlOa and at 20kg SIlOa was reverse.

• 대한화학회지
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• 제33권5호
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• pp.504-509
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• 1989

N,N'-dimethylethylenediamine-N,N'-di-${\alpha}$-butyric acid(dmedba)와 세자리 아미노산과의 코발트(III) 착물인 [Co(dmedba)(L-aa)] (L-aa = S-methyl-L-cysteine, L-methionine, L-glutamic acid, L-aspartic acid)는$ s-cis-[Co(dmedba)Cl_2]-^ 착물과 아미노산과의 반응으로부터 얻었다. 아미노산들은 [Co(dmedda)(L-dd)] 착물과 같이 아민과 카르복실그룹을 통하여 배위되었다. 이 착물들의 구조는 ^1H-NMR, IR, UV$ 스펙트럼 데이타와 원소분석으로 확인하였다.

• 한국미생물·생명공학회지
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• 제7권4호
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• pp.205-209
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• 1979

두유에서의 유산균 생육과 산생성량을 높일 수 있는 조건을 검토한 것을 요약하면 다음과 같다. 1. 유산균 Str. thermophilus, L. acidophilus, L. bulgaricus, 그리고 L. helveticus중에서 L. acidophilus가 두유에서의 생육이 가장 우수하였다. 2. 두유에 glucose, lactose 또는 sucrose를 각각 첨가했을 때 glucose의 첨가가 가장 L. acidophilus의 생육과 산생성에 효과가 있었다. 3. 우유보다 두유의 부족 필수아미노산인 methionine을 두유에 첨가했을 때 L. acidophilus의 생육과 산생성량을 상승시켰다. 4. 두유의 protease 처리는 L. acidophilus의 생육과 산생성을 크게 향상시켰고 산도는 비처리구보다 2배 이상 증가되었다.