• 한국동물학회지
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• 제4권2호
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• pp.13-19
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• 1961

Free amino acids at five different developemntal stages (Gastrulation-Hatching -out stage) of Hynobius leechi BOULENGER were analyzed qualitatively by the use of paper paitition chromatography. It was found that the number of free amino acids increased as the development proceeded. The free amino acids identified at each stages are as follows : Gastrulation stage : Alaninie, Aspartic acid, Glutamin acid, Histidine, Methionine. Neural plate formation stage : Alanine , Aspartic acid, Glutamic acid, Glycine, Histidine, MEthionine, Phenylalanine, Proline, Serine, Trypotophan. Middle tail-bud stage : Alanine, Arginine, Asparagine,Aspartic acid, Citrulline, Glutamic acid, Glycine, Histidie,Hydroxyproline, Proline, Leucine, Methionine, Ornithine, Phenylalanine, Serine, Threonine, Tryptophan. Late tail-bud stage : Alanine, Arginine, Asparagine, Aspartic acid, Citrulline, Glutamic acid. Glycine, Histidine, Hydroxyproline, Leucine, Methionine, Ornithine, Phenylalanine, Proline, Serine, Threonine, Tryptophan, Valine. Hatching -out stage : the same with the late tail-bud stage. It seems probable that the metabolic systems of amino acids before and after the middle tail-bud stage are quite different from each other. Before the middle tail=-bud stage, the reaction system of amino acids is thought not to be completed while after that stage the system has been completed , because in the former period of the development , the number of freeamino acids increased rapidly with the development , and after that stage, there is practically no change in the number of free amino acids.

• Asian-Australasian Journal of Animal Sciences
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• 제13권9호
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• pp.1235-1238
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• 2000

Thirty-six Holstein dairy cows were used to evaluate the effect of a rumen protected methionine supplement (RPMet). The cows were divided into two groups of 18 each (control/experimental). The experimental group was given 15 g/d of RPMet (Mepron $^{(R)}$M85, Degussa) from the 4th to the 26th week postpartum. All cows were fed a similar amount of forage including alfalfa silage, corn silage and timothy silage. Concentrate mixture was offered in proportion to the milk yield of each cow. Sufficiency of major metabolizable AAs was checked. Milk yield and milk composition was monitored for each individual cow. A metabolic profile test (MPT) was carried out at the 7th, 11th and 21st week postpartum. Without supplement, both methionine and leucine fell short of the daily requirement. Supplementation with 15 g/d RPMet was calculated to be within a sufficient margin of safety. Milk yield tended to remain higher in the supplemented group than in the controls during supplementation with RPMet. The differences in weekly milk production at the 17th, 18th, 19th and 22nd weeks postpartum were significantly high in the RPMet group (p<0.05). The average 305-d milk yield and the percentages of milk fat, milk protein and solids-not-fat were not affected by the treatment. No differences were observed in either the somatic cell count in the milk or the reproductive status. Judging from MPT, all the cows were in good health during lactation.

• Asian-Australasian Journal of Animal Sciences
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• 제19권8호
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• pp.1174-1178
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• 2006

An experiment was conducted to investigate the effects of dietary supplementation of copper chelates in the form of methionine, chitosan and yeast on the performance of laying hens. Four hundred ISA Brown layers, 84 wks old, were assigned to 4 treatments: control, 100 ppm Cu in methionine chelate (Met-Cu), 100 ppm Cu as chitosan chelate (Chitosan-Cu) and 100 ppm Cu as yeast chelate (Yeast-Cu). Each treatment had five replicates of 20 hens. Hen-day and hen-housed egg production and egg weight were significantly (p<0.05) increased by Met-Cu supplementation. The increase by Chitosan-Cu and Yeast-Cu supplementation was not significant. Contrast of the control vs. Cu chelates showed egg weight was significantly (p<0.05) increased by Cu chelate supplementation. Soft-shell egg production was significantly (p<0.05) reduced by supplementation of Cu chelates. Met-Cu treatment showed the lowest incidence of soft egg production. Gizzard erosion index was increased by Cu chelate supplementation. Crude fat in liver, total cholesterol in yolk and Cu content in liver and yolk were not significantly influenced by Cu chelate supplementation. It was concluded that dietary supplementation of 100 ppm Cu as Met-Cu significantly increased egg production and egg weight. Cu-Met chelate was also effective in reducing soft-shell egg production but increased gizzard erosion index.

• BMB Reports
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• 제35권2호
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• pp.228-235
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• 2002

Methionine aminopeptidase (MetAP) catalyzes the removal of an amino-terminal methionine from a newly synthesized polypeptide. The enzyme was purified to homogeneity from Bacillus stearothermophilus (KCTC 1752) by a procedure that involves heat precipitation and four sequential chromatographs (including DEAE-Sepharose ion exchange, hydroxylapatite, Ultrogel AcA 54 gel filtration, and Reactive red 120 dye affinity chromatography). The apparent molecular masses of the enzyme were 81,300 Da and 41,000 Da, as determined by gel filtration chromatography and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), respectively. This indicates that the enzyme is comprised of two identical subunits. The MetAP specifically hydrolyzed the N-terminal residue of Met-Ala-Ser that was used as a substrate, and exhibited a strong preference for Met-Ala-Ser over Leu-Gly-Gly, Leu-Ser-Phe, and Leu-Leu-Tyr. The enzyme has an optimal pH at 8.0, an optimal temperature at $80^{\circ}C$, and pI at 4.1. The enzyme was heat-stable, as its activity remained unaltered when incubated at $80^{\circ}C$ for 45 min. The Km and Vmax values of the enzyme were 3.0mM and 1.7 mmol/min/mg, respectively. The B. stearothernmophilus MetAP was completely inactivated by EDTA and required $Co^{2+}$ ion(s) for activation, suggesting the metal dependence of this enzyme.

• 한국식품영양과학회지
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• 제24권4호
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• pp.537-541
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• 1995

This study was designed to investigate the effects of methionine(Met) on the activities of heart lipid peroxidation related enzymes in ethanol administrated rats. Male Sprague-Dawley rats were fed on diets containing one of the three levels of Met(0%, 0.3%, 0.9% of kg diet) and ethanol(2.5g/kg of body weight) was administrated as 25v/v% ethanol to ethanol treated groups orally. The rats were sacrificed after 5 and 10 weeks of feeding. Xanthine oxidase(XO) and catalase activities increased with ethanol administration and those activities were higher n Met excessive and deficiency group than those of Met normal group at 5 and 10 weeks dieting. Superoxide dismutase(SOD) activity in heart decreased significantly in Met deficiency and Met excessive group as compared to that of control. Glutathione peroxidase(GSH-Px) activity in heart significantly decreased in Met deficiency group as compared to that of Met excessive and normal group. Glutathione S-transferase(GST) activity of heart tissue significantly increased by ethanol administration. Glutathione(GSH) content in heart decreased with ethanol administration and shwoed no significant differences with Met levels. Ethanol administration increased the content of lipid peroxide(LPO).

• Asian-Australasian Journal of Animal Sciences
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• 제29권5호
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• pp.689-694
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• 2016

The objective of the current study was to evaluate the effect of supplementation of either L-methionine (L-Met) or DL-methionine (DL-Met) to diets of starter pigs on nitrogen (N) balance, metabolism, and serum amino acid profile. Eighteen crossbred ($Duroc{\times}Landrace{\times}Yorkshire$) barrows weighing $15.45{\pm}0.88kg$ were randomly allotted to 1 of 3 diets with 6 pigs per treatment. The diets included a basal diet (Met-deficient diet) containing 0.24% standardized ileal digestibility Met with all other essential nutrients meeting the pig's requirements. The other two diets were produced by supplementing the basal diet with 0.12% DL-Met or L-Met. The experiment lasted for 18 days, consisting of a 13-day adaptation period to the diets followed by a 5-day experimental period. Pigs were fed ad libitum and free access to water throughout the experiment. Results showed that the supplementation of either L-Met or DL-Met improved N retention, and serum methionine concentration, and decreased N excretion compared with basal diet (p<0.01). The N retention of pigs fed diets supplemented with the same inclusion levels of DL-Met or L-Met were not different (p>0.05). In conclusion, on equimolar basis DL-Met and L-Met are equally bioavailable as Met sources for starter pigs.

• Current Research on Agriculture and Life Sciences
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• 제28권
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• pp.9-15
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• 2010

본 연구에서는 수수피에 함유된 천연색소에 대한 연구의 일환으로, 추출방법에 따른 색소 추출 효율과 저장안정제 첨가에 따른 저장 안정성과 특성을 검토하여 다음과 같은 결과를 얻었다. 1. 용액 추출 시 온도가 높을수록, 시간이 경과될수록 색소 추출 효율이 높게 나타났으며, pH 조건에서는 pH 4가 가장 효율적이었다. 2. 착액 추출 시, 단시간 전처리에서는 증류수가 pH 5에서보다 색소 추출량이 많았지만, 20시간 이상의 장시간 전처리에서는 오히려 pH 5에서 많게 나타났다. 3. 수수피 색소용액의 pH 변화에 따른 색도는, pH가 증가할수록 옅은 황색에서 짙은 황색을 거쳐 붉은색 톤으로 변화하였다. 4. 저장 안정제로 Methionine을 첨가한 결과에서는 첨가에 따른 수수피 색소의 안정화 효과에서 저장기간 18일까지는 변색 지연 효과를 보였으며, Methionine 10 mmol 첨가>20 mmol 첨가>무첨가 순으로 안정 효과가 크게 나타났다.

• Journal of Microbiology and Biotechnology
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• 제17권6호
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• pp.1010-1017
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• 2007

Two alternative pathways for methionine biosynthesis are known in Corynebacterium glutamicum: one involving transsulfuration (mediated by metB and metC) and the other involving direct sulfhydrylation (mediated by metY). In this study, MetB (cystathionine ${\gamma}-synthase$) and MetY (O-acetylhomoserine sulfhydrylase) from C. glutamicum were purified to homogeneity and the biochemical parameters were compared to assess the functional and evolutionary importance of each pathway. The molecular masses of the native MetB and MetY proteins were measured to be approximately 170 and 280 kDa, respectively, showing that MetB was a homotetramer of 40-kDa subunits and MetY was a homohexamer of 45-kDa subunits. The $K_m$ values for the O-acetylhomoserine catalysis effected by MetB and MetY were 3.9 and 6.4 mM, and the maximum catalysis rates were $7.4\;(k_{cat}=21\;S^{-1})\;and\;6.0\;(k_{cat}=28\;S^{-1})\;{\mu}mol\;mg^{-1}\;min^{-1}$, respectively. This suggests that both MetB and MetY can be comparably active in vivo. Nevertheless, the $K_m$ value for sulfide ions by MetY was 8.6mM, which was too high, considering the physiological condition. Moreover, MetB was active at a broad range of temperatures $(30\;and\;65^{\circ}C)$ and pH (6.5 and 10.0), as compared with MetY, which was active in a range from 30 to $45^{\circ}C$ and at pH values from 7.0 to 8.5. In addition, MetY was inhibited by methionine, but MetB was not. These biochemical data may provide insight on the role of the parallel pathways of methionine biosynthesis in C. glutamicum with regard to cell physiology and evolution.

• Asian-Australasian Journal of Animal Sciences
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• 제8권4호
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• pp.403-409
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• 1995

A growth experiment was conducted to evaluate the nutritivie values of supplemental lysine and methionine in broiler chicks. Two types of L-lysine, liquid and powder type, and DL-methionine were added to the diets at different levels of dietary protein with two growth phases, 0-3 weeks and 4-6 weeks named starter and grower, respectively. Six hundred seventy two chicks were allotted in 14 treatments; 3 controls by dietary CP level (starter-grower) with CP 23-21%, CP 21-19% and CP 20-18, 8 groups of liquid and powder lysine supplementation of 0.1, 0.2, 0.3 and 0.4%, and 3 groups of lysine and methionine supplementation. Body weight, feed intake, and excreta were measured and analyzed to determine growth performance, amino acid digestibilities, and the quantity of excreted nitrogen in feces. Chicks fed CP 23-20 with 3,200 ME kcal showed significantly better growth performance than those fed CP 21-18 for 6 weeks. The supplementation of 0.2% of either type of lysine to CP 21-19 diet improved weight gain and feed efficiecy to the extent that CP 23-21 diet was fed. Physical type of lysine did not affect chick's growth and amino acid digestibilities of the diets. The level of CP in the diet significantly affected nitrogen excretion in feces. Supplementation of lysine and methionine to CP 21-18 diet reduced fecal nitrogen by 10% compared to CP 23-21 diet. It was confirmed that 0.2% of supplemental lysine to the broiler diet spared the dietary protein by 3%, and also reduced nitrogen excretion in feces by 10%.

• 한국응용과학기술학회지
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• 제3권1호
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• pp.23-31
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• 1986

Several authors reported that vegetable proteins cause to decrease serum cholesterol and reported the effect of limiting amino acid balance in dietary protein on the blood component. This study was designed to observe growth rate and blood component in 1% cholesterol-fed male rats intake pure isolated soy proteins and methionine for 4 weeks. The diets were supplemented with either 20% casein or isolated soy protein as dietary protein sources and methionine as limiting amino acid of isolated soy protein and casein protein. The results were as follows; 1) The body weight gain was the greatest in casein groups. 2) Serum total cholesterol concentration was significantly increased by casein groups and slightly decreased by isolated soy protein groups. 3) Serum HDL-cholesterol concentration was significantly increased by isolated soy protein groups than control group. 4) Serum total lipid and triglyceride concentrations were significantly decreased by isolated soy protein groups than control group. 5) Serum glucose concentration was significantly increased by isolated soy protein plus 0.8% methionine than control group. 6) Serum total protein and albumin concentrations were significantly increased by all experimental diets groups than control group. Especially, casein groups were the most increased in all experimental diets groups.