• 핵의학기술
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• 제12권3호
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• pp.181-183
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• 2008

We developed simple and highly efficient synthesis method for [$^{11}C$]methionine using solid-phase extraction method. For synthesis, we used C18 cartridge. [$^{11}C$]methionine was synthesized on C18 cartridge according to the solid-phase [$^{11}C$]methylation of precursor L-homocysteine thiolactone hydrochloride. The radiochemical yields of [$^{11}C$]methionine was $48.9{\pm}7.93%$ decay corrected (results of 30 syntheses, mean$\pm$SD), with average production higher than 180 mCi. This procedure showed high yield and simple synthesis of [$^{11}C$]methionine.

• 한국식품영양과학회지
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• 제12권2호
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• pp.73-83
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• 1983

단백질(蛋白質)의 상호보충(相互補充) 및 제한(制限)아미노산 보충(補充)이 흰쥐(Sprague Dawley계(系) 이유(離乳)한 숫쥐)의 성장(成長), 체내대사(體內代謝) 및 체조성(體組成)에 미치는 영향(影響)을 규명하기 위하여 사양(飼養) 및 대사실험(代謝實驗)을 실시(實施)하였다. 실험사료(實驗飼料)의 에너지 및 단백질(蛋白質) 수준(水準)은 각각 3,600kcal/㎏ 및 20%로 고정하였고, 단백질(蛋白質)의 공급원(供給源)으로 카제인과 대두단백질(大豆蛋白質)을 택(擇)하여 각각 100:0, 80:20, 50:50, 20:80, 0:100의 비율(比率)로 혼합(混合)하였으며 각각에 methionine을 0% 또는 0.3%로 보충(補充)하였던 결과를 요약(要約)하면 다음과 같다. 흰쥐의 체중(體重)과 증체량(增體量)은 대두단백질(大豆蛋白質) 단독(單獨) 급여(給與) 때 가장 낮았고 카제인의 혼합비율(混合比率)을 증가(增加)시킬 수록 증가(增加)되었다. 대두단백질(大豆蛋白質)에 methionine을 보충급여(補充給與)했을 때 증체량(增體量)은 무보충(無補充) 혼합(混合) 급여(給與)했을 때와 동일(同一)했으며 카제인 단독(單獨) 급여(給與)때 보다 카제인 혼합(混合) methionine 보충(補充) 급여(給與)에서 증체량(增體量)은 더 높았다. 사료섭취량(飼料攝取量)은 카제인 단독급여(單獨給與) 때나 카제인의 혼합비율(混合比率)을 증가(增加)시킬 때 높았으나 meihionine을 보충(補充)했을 때 저하(低下)되었으며 대두단백질(大豆蛋白質) 단독급여(單獨給與)에서 낮았으며 methionine을 보충(補充)해도 증가(增加)되지 않았다. 사료효율(飼料效率)은 카제인이나 대두단백질(大豆蛋白質)의 단독(單獨) 급여(給與)때보다 두 단백질(蛋白質)의 혼합급여(混合給與) 때 더 높았으며 단독급여(單獨給與)에 methionine을 보충(補充)함으로써 사료효율(飼料效率)이 증가(增加)되었으나 혼합급여(混合給與)에 보충(補充)했을 때에는 같은 효과(效果)를 보이지 않았다. 성장실험기간중(成長實驗期間中) 총(總)에너지섭취량(攝取量)은 사료(飼料) 섭취량(攝取量)과 관계가 있었고 카제인 단독급여(單獨給與) 때나 그의 혼합비율(混合比率)을 증가(增加)시킬 때 증가(增加)했다. 에너지효율(效率)과 단백질효율(蛋白質效率)은 두 단백질(蛋白質)을 단독급여(單獨給與)할 때에는 methionine보충(補充)에 의해 증가(增加) 되었으며 또한 혼합급여(混合給與) 때에는 대두단백질(大豆蛋白質)의 비율(比率)을 증가(增加)시킬 수록 methionine에 의한 개선효과(改善效果)를 보였다. 질소섭취량(窒素攝取量) 및 카제인 뇨질소량(尿窒素量)은 단독급여(單獨給與) 했을 때 가장 높았고, 대두단백질(大豆蛋白質) 단독급여(單獨給與) 때 가장 낮았으며 카제인의 비율(比率)을 증가(增加)시킬 수로 증가(增加)되었다. 질소균형(窒素均衡) 및 축적율(蓄積率)은 처리(處理)에 의한 차이(差異)에 통계적(統計的) 유의성(有意性)은 없었다. 대사실험기간중(代謝實驗期間中) 총(總)에너지섭취량(攝取量)과 분(糞) 및 뇨(尿)에너지는 카제인 단독급여(單獨給與) 때 높았고, 가소화(可消化) 에너지와 대사(代謝)에너지, 에너지의 소화율(消化率) 및 리용율(利用率)은 처리(處理)에 의한 유의차(有意差)는 없었다. 체지방(體脂肪)은 methionine보충(補充)에 의해 증가(增加)되었으나, 체단백질(體蛋白質)은 감소(減少)했다(r=0.65, p<0.01). 체지방(體脂肪)과 체수분(體水分)과도 부(負)의 상관관계(相關關係)(r=-0.83, p<0.01)가 있었다. 간(肝)의 무게는 도체(屠體)의 무게의 변화(變化)와 일치(一致)했고 (r=0.79, p<0.01) methionine보충(補充)에 의해 증가(增加) 되었으며 카제인의 비율(比率)을 증가(增加)시킬 수록 증가(增加)되었다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권1호
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• pp.42-50
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• 2017

Objective: Two trials were conducted in order to examine the effects of level of supplemental methionine on productive performance, dietary energetic, plasma amino acid concentration, and digestive function. Methods: Dietary treatments consisted of a steam-flaked corn-based diet containing urea as the only source of supplemental nitrogen supplemented with no supplemental amino acid (control), or control plus 1.01% lysine and 0.032%, 0.064%, 0.096%, or 0.128% methionine. In Trial 1, 150 Holstein steer calves ($127{\pm}4.9kg$) were utilized to evaluate the influence of treatments on growth-performance, dietary energetic, plasma amino acid concentration during the first 112 days of growing period. During the initial 56-d period calves received the 5 experimental diets. During the subsequent 56-d period all calves were fed the control diet. Results: During the initial 56-d period, methionine supplementation increased (linear effect, p<0.01) plasma methionine. In the presence of supplemental lysine, increases on level of methionine in diet did not affect average daily gain. However, increased gain efficiency (quadratic effect, p = 0.03) and estimated dietary net energy (NE; linear effect, p = 0.05). Estimated metabolizable methionine supply was closely associated ($R^2=0.95$) with efficiency NE utilization for maintenance and gain. During the subsequent 56-d period, when all calves received the control diet (no amino acid supplementation), plasma amino acid concentrations and growth performance was not different among groups. However, the effects of methionine supplementation during the initial 56-period carried over, so that following a 56-d withdrawal of supplementation, the overall 112-d effects on gain efficiency (quadratic effect, p = 0.05) dietary NE (linear effect, $p{\leq}0.05$) remained appreciable. In Trial 2, 5 cannulated Holstein steers were used to evaluate treatment effects on characteristics of digestion and amino acid supply to the small intestine. There were no treatment effects on flow of dietary and microbial N to the small intestine. Postruminal N digestion increased (p = 0.04) with increasing level of supplemental methionine. Methionine supplementation linearly increased (p<0.01) duodenal flow of methionine. Likewise, lysine supplementation increased an average of 4.6% (p = 0.04) duodenal flow of lysine. In steers that received non-supplemented diet, observed intestinal amino acid supply were in good agreement with expected. Conclusion: We conclude that addition of rumen-protected methionine and lysine to diets may enhance gain efficiency and dietary energetics of growing Holstein calves. Observed amino acid supply to the small intestine were in good agreement with expected, supportive of NRC (2000, Level 1).

• 한국미생물·생명공학회지
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• 제17권6호
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• pp.611-618
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• 1989

Cephalosporium acremonium 균주로 미생물 고정화 증식입자를 제조하여 유동층 생물반응기에서 세파로스포린 C 생산에 대한 메치오닌의 영향에 대하여 연구하였다. 메치오닌은 세파로스포린 C 생합성에 매우 중요한 대사조절인자로 알려져 있는데, 본고에서는 초기 발효배지 내 메치오닌 농도의 영향과 이를 토대로 생물반응기에 메치오닌을 주입하였을 때 세파로스포린 C 생산에 미치는 메치오닌의 영향을 관찰하였다. 초기 배지 내에 존재하는 메치오닌에 의해 세파로스포린 C 생산성이 증가하였으며, 메치오닌의 최적양(0.3-0.5w/v％)이 존재하였다. 또한 메치오닌에 의해 탄소원의 소모속도가 증가됨이 관찰되었다. 배지내 메치오닌이 고갈될 때 세파로스포린 C 생산이 극대화되었으나 유동층 생물반응기에서 메치오닌을 부가적으로 첨가하였을 때 그 효과는 기대한 수준에 미치지 못했는데 이는 생체내 메치오닌의 축적과 관계가 있는 것으로 판단되었다. 또 고정화 증식입자를 사용하였을 때 세파로스포린 C 생산에 양호한 결과를 얻었는데 이 경우에도 적정량의 메치오닌 투여가 생산성에 중요한 인자임을 발견하였다. 따라서 유동층 반응기의 운전에 의해 세포로스포린 C 생산성을 향상시키기 위해서는 초기 운전단계에서 최적양의 메치오닌을 주입하는 것이 가장 중요하며 고정화 증식입자의 사용에 의해 공정생산성을 획기적으로 증대시킬 수 있다고 판단되었다.

• Archives of Pharmacal Research
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• 제27권1호
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• pp.25-30
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• 2004

Combinatorial homoserine lactone mixtures and individual products were obtained from the methionine-functionalized resin in solid-phase synthesis. The four-step process consisting of a coupling step of an N-Fmoc-L-methionine, deprotection of N-Fmoc group, N-coupling with a carboxylic acid, and cleavage reaction through a polymer supported strategy is described. Gas chromatography-mass selective detector (GC-MSD) techniques provide the most powerful methods for identifying both the combinatorial mixtures and individual products.

• 한국가금학회지
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• 제22권3호
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• pp.179-188
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• 1995

In Experiment 1, microbial assays were conducted on 57 feed ingredient samples to determine the content of total folic acid using Lactobacillus casei(ATCC 7469). Folic acid contents of feed samples pretreated with conjugase, ${\alpha}$-amylase, and a mixture of protease(Pronase)were corn, 09${\pm}$1.18($\pi$g${\pm}$SD); fish meal, 23.05${\pm}$1.27; milo, 29.34${\pm}$0.55; bakery meal, 25.80${\pm}$6.93; meat and bone meal, 56.76${\pm}$4.97; wheat middlings, 85.14${\pm}$2.56; and soybean meal, 193.97${\pm}$3.98. Experiments 2 and 3 were conducted to determine the effects of dietary supplemental folic acid and methionine on the performance of starting broiler chicks for 18 days. Four levels of dietary folic acid(0.24. 0.54,1.14 and 2.34mg/kg) and four levels of dietary methionine(0.45, 0.53,0.61, and 0.69%) were fed in a factorial design. The basal diet was based on corn, isolated soybean protein, meat and bone meal, and fish meal. It contained adequate amounts of all nutrients except methionine and folic acid in both experiments. Increased growth rate was observed in chicks fed the basal diet supplemented with either folic acid or methionine. Total dietary folic acid and methionine plus cysteine requirements for optimum growth were estimated to be 1.80 mg/kg and 0.89% in Experiment 2, and 1.47 mg/kg and 0.91% in Experiment 3, respectively. There were interactions between dietary folic acid and methionine on weight gain in both experiments. Chicks fed diets containing 2.34 mg folic acid /kg tended to display slow growth rate in both experiments. There was a significant linear feed conversion response to folic acid in Experiment 2, and a significant quadratic feed conversion resuonse to methionine in Experiment 3. There were both linear and quadratic liver folic acid responses to dietary folic acid in both experiments. There was no indication that dietary methionine had any effect on liver folic acid content. The incidence of tibial dyschondroplasia increased with increasing supplemental methionine, but were no significant differences detected at 5% level.

• 생명과학회지
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• 제19권3호
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• pp.343-348
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• 2009

벼도열병균은 벼의 주요 병해인 벼도열병의 원인균이다. 식물병원균의 침입 시 식물체로부터 발생하는 ROS는 식물의 방어기작으로 중요하며, 특히 아미노산의 하나인 methionine은 ROS에 의해 산화되어 methionine sulfoxide로 변화될 수 있다. 식물병원균은 식물체로 부터의 ROS에 의한 산화반응을 회피하기 위해 methionine sulfoxide reductase B (MSRB)와 같은 항산화 효소를 가지는데 본 연구에서는 벼도열병균에서의 MSRB 유전자를 동정하고 분자적 특성을 살펴보았다. MSRB 유전자는 벼도열병균의 게놈 상에 단일 유전자로 존재하며 과산화수소 처리에 의해 유전자발현이 다소 증가하는 경향을 보였다. 이러한 결과로 MSRB 유전자는 벼도열병균의 항산화 기작에 관여할 가능성이 높다고 판단된다.

• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1196-1203
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• 2010

In the present work, methanethiol and dimethyldisulfide were investigated as sulfur sources for methionine synthesis in Corynebacterium glutamicum. In silico pathway analysis predicted a high methionine yield for these reduced compounds, provided that they could be utilized. Wild-type cells were able to grow on both methanethiol and dimethyldisulfide as sole sulfur sources. Isotope labeling studies with mutant strains, exhibiting targeted modification of methionine biosynthesis, gave detailed insight into the underlying pathways involved in the assimilation of methanethiol and dimethyldisulfide. Both sulfur compounds are incorporated as an entire molecule, adding the terminal S-$CH_3$ group to O-acetylhomoserine. In this reaction, methionine is directly formed. MetY (O-acetylhomoserine sulfhydrylase) was identified as the enzyme catalyzing the reaction. The deletion of metY resulted in methionine auxotrophic strains grown on methanethiol or dimethyldisulfide as sole sulfur sources. Plasmid-based overexpression of metY in the ${\Delta}$metY background restored the capacity to grow on methanethiol or dimethyldisulfide as sole sulfur sources. In vitro studies with the C. glutamicum wild type revealed a relatively low activity of MetY for methanethiol (63 mU/mg) and dimethyldisulfide (61 mU/mg). Overexpression of metY increased the in vitro activity to 1,780 mU/mg and was beneficial for methionine production, since the intracellular methionine pool was increased 2-fold in the engineered strain. This positive effect was limited by a depletion of the metY substrate O-acetylhomoserine, suggesting a need for further metabolic engineering targets towards competitive production strains.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1804-1808
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• 2003

A layer experiment was conducted to determine the effects of supplementary methionine chelates (Cu, Zn and Mn), individual or in combination, on laying performance, eggshell quality, gizzard erosion, and IgG level of serum for 8 weeks. Five hundred 96-wk-old force molted ISA Brown layers were assigned to five dietary treatments. Basal diet was formulated to meet or exceed the nutrients requirements listed in NRC (1994). Five experimental diets were control, Zn-methionine chelate (Zn-Met) supplemented, Cumethionine chelate (Cu-Met) supplemented, Zn-Mn-methionine chelate (Zn-Mn-Met) supplemented and Zn-Mn-Cu-Met supplemented diet. Each treated diet was supplemented with respective mineral(s) at the level of 100 ppm in the form of methionine chelate. Egg production was increased by Cu-Met supplementation but decreased by Zn-Met supplementation. Egg weight was significantly (p<0.05) lower in Cu-Met treatment than those of the control and Zn-Met treatment. Specific gravity of eggs and eggshell strength were highest and soft egg production was lowest in Cu-Met treatment. Gizzard erosion index was significantly increased by supplementation of Cu-Met, Zn-Mn-Met or Zn-Mn-Cu-Met. Zinc content in liver significantly increased by Zn-Met, but not by Zn-Mn-Cu-Met treatment. In conclusion, 100 ppm Cu in Cu-Met chelate improved laying performance and eggshell quality but also increased gizzard erosion index. Supplementation of Zn-Met or its combination with other mineral chelates had no beneficial effects on laying performance and eggshell quality.

• Asian-Australasian Journal of Animal Sciences
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• 제17권1호
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• pp.102-108
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• 2004

The present experiment was conducted to assess the efficacy of methionine hydroxy analogue free fatty acid (MHAFA) in comparison to DL-methionine (DL-Met) utilizing day-old commercial broiler chicks (n=300). The chicks were randomly distributed into 30 groups of 10 chicks each. Three dietary treatments, viz. D1-maize-soybean meal based basal diet (Control), D2- control diet supplemented with DL- methionine to meet its requirements and D3-control supplemented with MHA-FA @ 1.54 times of DL-methionine used in D2, were formulated. Each dietary treatment was offered to 10 replicated groups of chicks following completely random design (CRD). The chicks fed on supplemental DL-Met had significantly higher (p<0.01) gain in body weight, followed by MHA-FA group and control during 0-3 weeks of age. During overall growth period (0-6 weeks), chicks in DL-Met and MHA-FA groups grew better (p<0.01) than those in control. Feed conversion ratio (FCR) improved (p<0.01) on supplementation of either DL- Met or MHA-FA in the basal (Control) diet during 0-3 weeks of age. The FCR for overall period, however, did not differ statistically (p>0.05) amongst the treatments. The eviscerated yields emanated from diets with DL-Met or MHA-FA were higher (p<0.01) than that in Control. Abdominal fat pad was also more (p<0.01) in broilers fed control diet than in DL-Met or MHA-FA supplemented group. Breast yield was higher (p<0.05) in MHA-FA fed broilers than those fed DL-methionine supplemented or un-supplemented diets. The efficacy of MHA-FA in comparison to DL-Met for growth was 62.11, 64.82 and 63.88% and for feed efficiency was 62.98, 67.73 and 64.01% at 0-3, 3-6 and 0-6 weeks of age, respectively, while it was 65.85, 71.40 and 67.49% for eviscerated yield, abdominal fat pad reduction and breast yield at 6 weeks of age, respectively.