• 대한핵의학회지
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• 제26권1호
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• pp.140-146
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• 1992

$^{99m}Tc-Methionine$ complexes from enantiomeric and racemic methionines were prepared controlling reaction parameters such as pH and the concentration of stannous chloride. Some radiochromato-graphic systems were also examined to determine the labelling yields of $^{99m}Tc$ complexes. The best resolutions of $^{99m}Tc$ complexes were obtained at ITLC-SA developed with acetone and paper chromatography with n-butanol saturated with 0.3N HCI. In the former system, $HR-{99m}Tc$ and $^{99m}Tc-methionine$ complex remained at origin, while $^{99m}TcO_4^-$ moved with Rf value of 1.0. In latter process, $HR-^{99m}Tc$ stayed at the origin, while $^{99m}TcO_4^-\;and\;^{99m}Tc-methionine$ complexes moved with Rf value of 0.5. By combining of two chromatographic systems, the contents of three $^{99m}Tc$ species were calculated easily. $^{99m}Tc$ Labelling from enantiomeric and racemic methionines had little differences and the optimal condition was found at pH 9.00 and the molar ratio of methionine to stannous chloride of 24:1. The yields of $^{99m}Tc$ complexes from D-, L-, and DL-methionines were 87.6%, 94.1%, and 97.9%, respectively. The results indicated that methionine containing relatively hydrophobic methylthio group $(-SCH_3)$ would be labelled with $^{99m}Tc$ by stannous chloride method.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.948-953
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• 2007

The relative performance and immune response was evaluated in White Leghorn layers fed liquid DL-methionine hydroxyl analogue-free acid (MHA-FA) relative to dry DL-methionine (DLM) in maize-soybean-sunflower based diets. Three graded levels of methionine (Met) from DLM or MHA-FA were added to the basal diet containing 0.27% Met on an equimolar basis to achieve 0.30, 0.36 and 0.42% Met in the diet. Each diet was fed ad libitum to 25 replicates of one bird (individual feeding) each, from 24 to 40 weeks of age. A regime of 16 h light was provided and all the layers were kept under uniform management throughout the experimental period. None of the parameters studied were influenced by the interaction between source and level of Met in diets. Similarly, the majority of parameters, except for daily feed consumption and immune response (influenced by level) and egg specific gravity and shell thickness (influenced by source), were not affected by either source or level of Met in the diets. Feed consumption was significantly lower in the birds fed a diet containing 0.42% Met compared to those fed lower levels of Met. The cutaneous basophilic hypersensitivity response to PHA-P and antibody titre (32 and 40 wk) to inoculation of sheep red blood cells increased significantly by increasing the concentration of Met in the diet from 0.30 to 0.36%. Thus, the Met requirement for immune competence was higher than for optimum production. The source of Met significantly influenced the egg specific gravity and shell thickness. The specific gravity and shell thickness of eggs increased significantly when MHA-FA was used as the source of Met in the diet compared to DLM. From the study it is concluded that Met requirement for immune competence (360 mg/b/d) is higher than for optimum production (300 mg/b/d). MHA-FA was comparable with DLM as a source of Met for production performance and immunity, when the bioavailability of MHA-FA was considered as 88% of DLM. Further, MHA-FA improved egg shell quality compared to DLM.

• Asian-Australasian Journal of Animal Sciences
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• 제21권6호
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• pp.831-837
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• 2008

The objective of this study was to evaluate the effects of ruminally-protected methionine supplementation (0, 7, or 14 g/head/d) on nutrient intake, digestibility, growth performance, carcass, and meat characteristics of Awassi ram lambs fed finishing diets. Twenty four Awassi ram lambs ($16.8{\pm}1.17kg$ body weight) were randomly assigned to 3 treatment diets (8 lambs/treatment) and housed in individual pens. Lambs were given an adaptation period of 7 days before the intensive feeding period that lasted for 86 days. On day 74 of the trial, a digestibility experiment was performed. At the end of the trial (d 86), all lambs were slaughtered to evaluate carcass characteristics and meat quality. Increasing the level of methionine supplementation did not improve (p>0.05) performance nor feed conversion ratio. Nutrient intake and digestibilities were not influenced (p>0.05) by methionine supplementation. There were no differences in final weight, hot and cold carcass weights, dressing percentages or any of the measured non-carcass components. Tissues and fat depth measurements together with all meat quality attributes measured on longissimus muscle of the loin cut were not affected by methionine supplementation. The only meat quality parameters affected were redness (a*) and the hue angle being higher for the control group (p<0.05). These results suggest that methionine supplementation is not likely to produce any production benefits in nutrient digestibilities, performance or carcass characteristics of ram lambs fed a high performance diet.

• 한국가금학회지
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• 제44권2호
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• pp.67-73
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• 2017

The purpose of our study was to determine the effects of varying levels of energy, protein, and amino acids on the performances of laying hens. A total of 240 Hy-Line Brown laying hens at 36 weeks of age were used in this 4-week feeding trial. The hens were randomly allocated to five treatment diets, with eight replications of six hens in each replicate cage. The treatment diets were as follows: A- basal diet + 18% crude protein, metabolizable energy 2,800 kcal, total (methionine + cysteine) 0.65%; B- basal diet + 17% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.59%; C- basal diet + 16.5% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.59%; D- basal diet + 16.5% crude protein, metabolizable energy 2,700 kcal, total (methionine + cysteine) 0.54%; and E- basal diet + 16% crude protein, metabolizable energy 2,680 kcal, total (methionine + cysteine) 0.54%. The study results revealed that the hen-day egg production of hens that were fed with low-energy diets (B, C, and D) was comparable with that of hens fed with high-energy diet A, whereas average daily feed intake in hens fed treatment diet D and E was significantly higher (P<0.05) than that in hens fed treatment diet A. Overall, the eggshell thickness was unaffected by any of the treatment diets. Egg weight was comparable among the treatment diets, except for treatment diet E. Haugh unit improved with decreasing levels of dietary energy, protein, and methionine + cysteine in the diet. We can summarize that laying hens fed with low dietary energy and low crude protein treatment diets B, C, and D had satisfactory performance compared with those fed with high-energy treatment diet A. This indicates that there is the potential to reduce feed costs by formulating diets with lower energy and low protein levels.

• Asian-Australasian Journal of Animal Sciences
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• 제2권3호
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• pp.226-227
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• 1989

• Journal of Animal Science and Technology
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• 제44권4호
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• pp.399-406
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• 2002

Methionine chelate 형태로 Cu 및 Zn의 첨가가 육계의 생산성과 영양소 이용률, 혈청 IgG 수준, 근위의 손상정도(gizzard erosion index) 그리고 간과 배설물의 Cu와 Zn 함량에 미치는 영향을 알아보기 위해 갓 부화한 1,000수의 Ross$^{(R)}$ 병아리를 4처리 5반복, 반복당 50수(암수 각각 25수씩)를 배치하여 5주간 사양시험을 실시하였다. 시험사료는 대조구 사료에 Cu와 Zn를 methionine chelate 형태로 100 ppm씩 단독 또는 혼합첨가하여 만들었다. 증체량은 chelate 첨가구들 모두 대조구 보다 높았고(P<0.05), 사료요구량은 chelate 첨가구들이 대조구 보다 낮았다(P<0.05). Cu와 Zn를 혼합하여 첨가한 처리구의 증체량과 사료효율은 Cu와 Zn를 단독 첨가한 처리구들보다 높은 경향을 나타냈다. 영양소 이용률은 Cu 및 Zn chelate 첨가에 의해 유의한 영향을 받지 않았다. 혈청 IgG 농도는 Cu와 Zn chelate 혼합처리구가 대조구에 비해 유의하게 높았으나(P< 0.05), 근위 궤양 정도는 처리에 따른 차이가 없었다. 간과 배설물 내 Cu 및 Zn 함량은 사료에서 이들 광물질의 함량에 의해 영향을 받았다(P<0.05). 결론적으로 Cu와 Zn chelate 단독 또는 혼합하여 첨가시 육계의 증체량과 사료효율을 개선시키고 혈청 IgG 농도를 증가시키며 간 내 Cu와 Zn 수준은 유의한 영향을 받지 않으나 분 내 Cu와 Zn의 함량은 증가시키는 것으로 나타났다.

• Journal of Animal Science and Technology
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• 제44권6호
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• pp.727-738
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• 2002

본 시험은 각각의 필수아미노산 결핍사료 섭취에 의한 단기간의 섭식반응과 methionine 결핍(-Met) 사료 섭취시 뇌내 각 부위에 나타나는 Fos 면역반응을 조사하여 아미노산 결핍이 뇌내 섭식반응과 관련있는 부위를 명확히 알고자 수행하였다. 실험사료의 단백질원은 정제아미노산을 이용하였다. 시험에 이용된 모든 사료의 질소원은 순수 아미노산 혼합물을 이용하였으며, 사료내 단백질 함량은 15%로 하였다. 사료는 하루 6시간 동안 섭취하도록 적응을 시켰으며(17:00${\sim}$21:00, meal feeding method), 사료섭취량과 증체량은 사료급여 7일째부터 매시간 측정하였다. 실험 1에서는 각 필수아미노산 결핍사료가 사료섭취량, 체중 변화 및 섭식패턴에 미치는 영향을 관찰하였고, 실험 2에서는 Fos 면역조직 화학적 방법을 사용하여 methio- nine 결핍사료에 대하여 회피 반응을 나타내는 동안에 활성을 보이는 뇌의 영역을 확인하였다. 각 필수아미노산 결핍사료 섭취에 따른 초기 섭식 억제 정도는 methionine이 가장 강하게 나타난 반면 threonine이 가장 약하였다. 결핍사료 급여 3일째의 사료섭취량은 대조구 사료에 비하여 histidine(71%), leucine(68%), isoleucine (66%), threonine(63%), tryptophan(61%), valine (55%), phenylalanine(52%), methionine(51%), lysine(44%), arginine(24%) 순으로 억제되었다. 뇌 신경 영역에 Fos 면역활성은 PPC, amygdala 및 endopyriform cortex(EPC) 부분이 대조구에 비하여 강한 활성을 나타냈으나, LH, VMH 및 PVM에서는 대조구와 처리구가 비슷하게 나타냈다. 따라서 본 연구의 결과로 미루어 뇌내 PPC는 필수아미노산 결핍에 반응하는 초기 인식부위라는 것을 확인할 수 있었다.

• BMB Reports
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• 제44권10호
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• pp.669-673
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• 2011

Human methionine sulfoxide reductase B3A (hMsrB3A) is an endoplasmic reticulum (ER) reductase that catalyzes the stereospecific reduction of methionine-R-sulfoxide to methionine in proteins. In this work, we identified an antimicrobial peptide from hMsrB3A protein. The N-terminal ER-targeting signal peptide (amino acids 1-31) conferred an antimicrobial effect in Escherichia coli cells. Sequence and structural analyses showed that the overall positively charged ER signal peptide had an Argand Pro-rich region and a potential hydrophobic ${\alpha}$-helical segment that contains 4 cysteine residues. The potential ${\alpha}$-helical region was essential for the antimicrobial activity within E. coli cells. A synthetic peptide, comprised of 2-26 amino acids of the signal peptide, was effective at killing Gram-negative E. coli, Klebsiella pneumoniae, and Salmonella paratyphi, but had no bactericidal activity against Gram-positive Staphylococcus aureus.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.279-288
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• 1994

Three experiments were conducted with female Japanese Saanen goats to investigate the effects of rumen protected methionine (RPMet) on N utilization and whole-body protein turnover. Whole-body leucine flux from which whole-body protein turnover rates were derived was measured by primed- continuous infusion of L-[$^{15}N$] leucine in combination with gas chromatography-mass spectrometry. Throughout the experiments RPMet was added to a diet to supply 1.5 g DL-methionine per goat per day. Irrespective of the major N sources (i.e., protein or urea) in the diet, both N deposition and whole-body protein synthesis were increased (p<0.05), and urinary N excretion was decreased (p<0.05) by supplementing with RPMet, but not by supplementing with methionine. It was concluded, therefore, that under the present experimental conditions, the RPMet supplement was efficiently bypassed to result in enhanced body protein synthesis of the goat.

• BMB Reports
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• 제44권12호
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• pp.805-810
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• 2011

Methionine sulfoxide reductase A (MSRA) is a ubiquitous enzyme that has been demonstrated to reduce the S enantiomer of methionine sulfoxide (MetSO) to methionine (Met) and can protect cells against oxidative damage. In this study, we isolated a novel MSRA (SlMSRA2) from Micro-Tom (Solanum lycopersicum L. cv. Micro-Tom) and characterized it by subcloning the coding sequence into a pET expression system. Purified recombinant protein was assayed by HPLC after expression and refolding. This analysis revealed the absolute specificity for methionine-S-sulfoxide and the enzyme was able to convert both free and protein-bound MetSO to Met in the presence of DTT. In addition, the optimal pH, appropriate temperature, and $K_m$ and $K_{cat}$ values for MSRA2 were observed as 8.5, $25^{\circ}C$, $352{\pm}25\;{\mu}M$, and $0.066{\pm}0.009\;S^{-1}$, respectively. Disk inhibition and growth rate assays indicated that SlMSRA2 may play an essential function in protecting E. coli against oxidative damage.