• 제목/요약/키워드: amino acids requirement

검색결과 58건 처리시간 0.032초

각기 다른 단백질섭취 수준에서 본 식이단백질의 질이 단백질대사에 미치는 영향 -Simulation Model을 이용하여- (Simulation of the Effect of Protein Quality at the Different Protein Intake Level on Protein Metabolism)

  • 이옥희
    • Journal of Nutrition and Health
    • /
    • 제26권9호
    • /
    • pp.1033-1048
    • /
    • 1993
  • This study was designed to describe the effect of the protein quality at different intake level of protein on the protein metabolism in the whole body of growing pigs with a simulation model. Varying to the protein level in feeds, four simulations were conducted. The feed protein level, represented as proportions of digestible protein to the metabolic energy (DP/ME, g/MJ), were 6-8, 11-13, 17-19, and 23-25 DP/ME, respectively. Two protein quality and six weeks of growth time were used at each simulation. The objective function for the simulations was protein deposition in the whole body, which was calculated from the experimental results. The parameters in the simulation were determined by the parameter estimation technique. The results obtained from the simulation were as follows: The protein synthesis and breakdown rates(g/day) in the whole body was increased with the increase of protein quality only at lower or required level of protein intake. They showed a parallel behavior in the course of growth, irrespective of quality and level of feed protein intake. The simulated protein deposition and protein synthesis showed a linear relationship between them at different protein quality and level. The affinity parameter showed a linear relationship between them at different protein quality and level. The affinity parameter showed that arginine, tryptophan and isoleucine were more efficient in the stimulation ofbody protein synthesis. Lysine and phenylalanine+tyrosine were less efficient. The oxidation parameter showed that histidine, pheyalanine+tyrosine were less efficient. The oxidation parameter showed that histidine, phenyalanine+tyrosine, and methionine+cystine were oxidized in larger magnitude than lysine and threonine. The oxidation parameter of most amino acids increased with the increase of protein intake beyond the requirement level, but not any more at highest protein intake level. Finally it was found that the improvement of feed protein quality at the lower or required level of protein intake increase protein deposition through a parallel increase of protein synthesis and breakdown.

  • PDF

Biosynthesis of Apigenin Glucosides in Engineered Corynebacterium glutamicum

  • Obed Jackson Amoah;Samir Bahadur Thapa;Su Yeong Ma;Hue Thi Nguyen;Morshed Md Zakaria;Jae Kyung Sohng
    • Journal of Microbiology and Biotechnology
    • /
    • 제34권5호
    • /
    • pp.1154-1163
    • /
    • 2024
  • Glucosylation is a well-known approach to improve the solubility, pharmacological, and biological properties of flavonoids, making flavonoid glucosides a target for large-scale biosynthesis. However, the low yield of products coupled with the requirement of expensive UDP-sugars limits the application of enzymatic systems for large-scale. C. glutamicum is a Gram-positive and generally regarded as safe (GRAS) bacteria frequently employed for the large-scale production of amino acids and biofuels. Due to the versatility of its cell factory system and its non-endotoxin producing properties, it has become an attractive system for the industrial-scale biosynthesis of alternate products. Here, we explored the cell factory of C. glutamicum for efficient glucosylation of flavonoids using apigenin as a model flavonoid, with the heterologous expression of a promiscuous glycosyltransferase, YdhE from Bacillus licheniformis and the endogenous overexpression of C. glutamicum genes galU1 encoding UDP-glucose pyrophosphorylase and pgm encoding phosphoglucomutase involved in the synthesis of UDP-glucose to create a C. glutamicum cell factory system capable of efficiently glucosylation apigenin with a high yield of glucosides production. Consequently, the production of various apigenin glucosides was controlled under different temperatures yielding almost 4.2 mM of APG1(apigenin-4'-O-β-glucoside) at 25℃, and 0.6 mM of APG2 (apigenin-7-O-β-glucoside), 1.7 mM of APG3 (apigenin-4',7-O-β-diglucoside) and 2.1 mM of APG4 (apigenin- 4',5-O-β-diglucoside) after 40 h of incubation with the supplementation of 5 mM of apigenin and 37℃. The cost-effective developed system could be used to modify a wide range of plant secondary metabolites with increased pharmacokinetic activities on a large scale without the use of expensive UDP-sugars.

ENZYMATIC STUDIES ON VITAMIN B6 METABOLISM

  • Kim, Young-Tae
    • 한국어병학회지
    • /
    • 제6권2호
    • /
    • pp.133-142
    • /
    • 1993
  • 비타민은 동물과 어류에 있어 성장, 발육, 및 대사기능에 비교적 적은 양으로 요구되는 필수 미량원소이다. 이들 미세 영양분이 결핍됨으로써 식욕 감퇴에서부터 심한 조직 변형등의 증상들을 일으킨다. 수용성 vitamin B6는 비교적 적은양이 요구되며, 주로 보조 효소 기능을 가지고 있다. 비타민 B6라는 명칭은 유사한 대사 기능들을 가진 화학적으로 관련된 pyridoxine, pyridoxamine, pyridoxal들을 의미한다. 비타민 B6는 비 반추 포유류, 조류와 어류의 음식물을 통해 섭취되는 성분이며, 비타민 B6 화합물들은 식물과 미생물 등에 의해 합성된다. 대사적으로 활성형인 비타민 B6 보조효소는 pyridoxal-5-phsphate(PLP)이며, decarboxylases, aminotransferases, sulfhydrases, tryptophanases를 포함한 아미노산 대사에 관여하는 여러 효소들(PLP-dependant)에 coenzyme으로 작용한다. 비타민 B6 요구량이 육식 동물보다 고단백질을 섭취하는 어류에서 더 높다. B6는 탄수화물과 지질의 대사에도 역시 관여하며 heme과 serotonin의 합성에 필수적이다. 어류에서 결핍증(현상)은 빨리 나타나는데, 이러한 증세로는 신경계 분열, 경련, 유영 부조화, 피부병변, 부종, 안구 돌출, 근 긴장성 경련 등이 포함된다. 비타민 B6는 pyridoxal kinase와 pyridoxine(pyridoxamine) oxidase의 촉매 반응에 의해 생체내 활성형인 PLP로 된다. PLP는 PLP-의존성 효소에서 보조 효소로 필수적인 역할을 하는 관계로 이 논문에서는 비타민 B6 생합성 및 대사와 비타민 B6 의존성 효소(aminotransferase)의 특성과 작용기작에 대한 효소학적 연구를 중점으로 이들 enzyme들의 구조와 기능에 대한 최근 연구 동향을 살펴보고자 한다.

  • PDF

유유아(乳幼兒) 및 성장기 아동을 위한 영양식품 개발에 관한 연구 (1) 제품의 조제(調製) 및 그 성상(性狀) (Development of Protein-rich Food Mixtures for Infants and Growing Children in Korea (I) Preparation, Chemical Compositions and Rheological Properties of the Mixtures)

  • 최홍식;권태원
    • 한국식품과학회지
    • /
    • 제2권1호
    • /
    • pp.96-103
    • /
    • 1970
  • 우리나라의 여러가지 현실정을 고려해볼 때 모든 영양소의 보급원이 될 수 있으며 값이 바서 농어촌 어린이까지 널리 이용할 수 있는 영양식품의 개발은 대단히 시급하고도 중요한 일이다. 이 연구에서는 그 개발을 위하여 몇 가지 농산물을 주원료로 적절히 가공하고 여기에 FPC 효모 경화유 비타민 무기질 등을 첨가한 새로운 분말식품을 제조하고, 이에 대한 이화학적 성상을 조사하였다. 가. 시제품은 담황색 분말로서 순한 향취를 가지며 ;water absorption index, 320; 총균수, $10^4/g$ 이하:sedimentation value, 63: Bostwick consistency value, 15cm/30% 및 ring test value, 23cm/30% 이었다. 나. 단백질을 22-25% 함유하는 이 시제품은 FAO표준구성(1957)을 기준으로 할 때 주제한아미노산이 총 함유황아미노산이며, 단백가는 F-F-3가 45, F-P-4는 75이었다. 그러나 수정된 FAO 표준구성(1965)과 비교해보면 threonine이 제한아미노산이며 이 때의 F-P-4의 단백가는 93이었다. 한편 Holt 등이 제안한 유아필수아미노산 소요량을 F-P-4와 비교한 결과 12 개월된 유아의 하루 소요량을 P-P-4 130g으로서 대체로 만족시키고 있었다. 다. 비타민 및 무기질 함량을 분석 조사한 결과 이 제품 100g으로서도 유유아의 1일 권장량을 대채로 충족시킬 수 있었다.

  • PDF

The effect of nanoemulsified methionine and cysteine on the in vitro expression of casein in bovine mammary epithelial cells

  • Kim, Tae-Il;Kim, Tae-Gyun;Lim, Dong-Hyun;Kim, Sang-Bum;Park, Seong-Min;Lim, Hyun-Joo;Kim, Hyun-Jong;Ki, Kwang-Seok;Kwon, Eung-Gi;Kim, Young-Jun;Mayakrishnan, Vijayakumar
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제32권2호
    • /
    • pp.257-264
    • /
    • 2019
  • Objective: Dairy cattle nutrient requirement systems acknowledge amino acid (AAs) requirements in aggregate as metabolizable protein (MP) and assume fixed efficiencies of MP used for milk protein. Regulation of mammary protein synthesis may be associated with AA input and milk protein output. The aim of this study was to evaluate the effect of nanoemulsified methionine and cysteine on the in-vitro expression of milk protein (casein) in bovine mammary epithelial cells (MAC-T cells). Methods: Methionine and cysteine were nonionized using Lipoid S 75 by high-speed homogenizer. The nanoemulsified AA particle size and polydispersity index were determined by dynamic light scattering correlation spectroscopy using a high-performance particle sizer instrument. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to determine the cytotoxicity effect of AAs with and without nanoionization at various concentrations (100 to $500{\mu}g/mL$) in mammary epithelial cells. MAC-T cells were subjected to 100% of free AA and nanoemulsified AA concentration in Dulbecco's modified Eagle medium/nutrient mixture F-12 (DMEM/F12) for the analysis of milk protein (casein) expression by the quantitative reverse transcription polymerase chain reaction method. Results: The AA-treated cells showed that cell viability tended to decrease (80%) in proportion to the concentration before nanogenesis, but cell viability increased as much as 90% after nanogenesis. The analysis of the expression of genetic markers related to milk protein indicated that; ${\alpha}_{s2}$-casein increased 2-fold, ${\kappa}$-casein increased 5-fold, and the amount of unchanged ${\beta}$-casein expression was nearly doubled in the nanoemulsified methionine-treated group when compared with the free-nanoemulsified methionine-supplemented group. On the contrary, the non-emulsified cysteine-administered group showed higher expression of genetic markers related to milk protein ${\alpha}_{s2}$-casein, ${\kappa}$-casein, and ${\beta}$-casein, but all the genetic markers related to milk protein decreased significantly after nanoemulsification. Conclusion: Detailed knowledge of factors, such nanogenesis of methionine, associated with increasing cysteine and decreasing production of genetic markers related to milk protein (casein) will help guide future recommendations to producers for maximizing milk yield with a high level of milk protein casein.

해조의 식용분말화에 관한 연구 (A Study on the Nutritive Value and Utilization of Powdered Seaweeds)

  • 유정열;이기열;김숙희
    • Journal of Nutrition and Health
    • /
    • 제8권1호
    • /
    • pp.15-37
    • /
    • 1975
  • I. Subject of the study A study on the nutritive value and utilization of powdered seaweeds. II. Purpose and Importance of the study A. In Korea the shortage of food will be inevitable by the rapidly growing population. It will be very important study to develop a new food from the seaweeds which were not used hitherto for human consumption. B. The several kinds of seaweeds have been used by man in Korea mainly as side-dishes. However, a properly powdered seaweed will enable itself to be a good supplement or mixture to certain cereal flours. C. By adding the powdered seaweed to any cereals which have long been staple foods in this country the two fold benefits; saving of cereals and change of dietary pattern, will be secured. III. Objects and scope of the study A. Objects of the study The objects will come under four items. 1. To develop a powdered seaweed as a new food from the seaweeds which have been not used for human consumption. 2. To evaluate the nutritional quality of the products the analysis for chemical composition and animal feeding experiment will be conducted. 3. Experimental cocking and accepability test will be conducted for the powdered products to evaluate the value as food stuff. 4. Sanitary test and also economical analysis will be conducted for the powdered products. B. Scope of the study 1. Production of seaweed powders Sargassum fulvellum growing in eastern coast and Sargassum patens C.A. in southern coast were used as the material for the powders. These algae, which have been not used for human consumption, were pulverized through the processes of washing, drying, pulverization, etc. 2. Nutritional experiments a. Chemical composition Proximate components (water, protein, fat, cellulose, sugar, ash, salt), minerals (calcium, phosphorus, iron, iodine), vitamins (A, $B_1,\;B_2$ niacin, C) and amino acids were analyzed for the seaweed powders. b. Animal feeding experiment Weaning 160 rats (80 male and 80 female rats) were used as experimental animals, dividing them into 16 groups, 10 rats each group. Each group was fed for 12 weeks on cereal diet (Wheat flour, rice powder, barley powder, potato powder, corn flour) with the supplementary levels of 5%, 10%, 15%, 20% and 30% of the seaweed powder. After the feeding the growth, feed efficiency ratio, protain efficiency ratio and ,organs weights were checked and urine analysis, feces analysis and serum analysis were also conducted. 3. Experimental cooking and acceptability test a. Several basic studies were conducted to find the characteristics of the seaweed powder. b. 17 kinds of Korean dishes and 9 kinds of foreign dishes were prepared with cereal flours (wheat, rice, barley, potato, corn) with the supplementary levels of 5%, 10%, 15%, 20% and 30% of the seaweed powder. c. Acceptability test for the dishes was conducted according to plank's Form. 4. Sanitary test The heavy metals (Cd, Pb, As, Hg) in the seaweed powders were determined. 5. Economical analysis The retail price of the seaweed powder was compared with those of other cereals in the market. And also economical analysis was made from the nutritional point of view, calculating the body weight gained in grams per unit price of each feeding diet. IV. Results of the study and the suggestion for application A. Chemical composition 1. There is no any big difference in proximate components between powders of Sargassum fulvellum in eastern coast and Sargassum patens C.A. in southern coast. Seasonal difference is also not significant. Higher levels of protein, cellulose, ash and salt were found in the powders compared with common cereal foods. 2. The levels of calcium (Ca) and iron (Fe) in the powders were significantly higher than common cereal foods and also rich in iodine (I). Existence of vitamin A and vitamin C in the Powders is different point from cereal foods. Vitamin $B_1\;and\;B_2$ are also relatively rich in the powders.'Vitamin A in ·Sargassum fulvellum is high and the levels of some minerals and vitamins are seemed4 to be some influenced by seasons. 3. In the amino acid composition methionine, isoleucine, Iysine and valine are limiting amino acids. The protein qualities of Sargassum fulvellum and Sargassum patens C.A. are seemed to be .almost same and generally ·good. Seasonal difference in amino acid composition was found. B. Animal feeding experiment 1. The best growth was found at.10% supplemental level of the seaweed Powder and lower growth rate was shown at 30% level. 2. It was shown that 15% supplemental level of the Seaweed powder seems to fulfil, to some extent the mineral requirement of the animals. 3. No any changes were found in organs development except that, in kidney, there found decreasing in weight by increasing the supplemental level of the seaweed powder. 4. There is no any significant changes in nitrogen retention, serum cholesterol, serum calcium and urinary calcium in each supplemental level of the seaweed powder. 5. In animal feeding experiment it was concluded that $5%{\sim}15%$ levels supplementation of the seaweed powder are possible. C. Experimental cooking and acceptability test 1. The seaweed powder showed to be utilized more excellently in foreign cookings than in Korean cookings. Higher supplemental level of seaweed was passible in foreign cookings. 2. Hae-Jo-Kang and Jeon-Byung were more excellent than Song-Pyun, wheat cake, Soo-Je-Bee and wheat noodle. Hae-Je-Kang was excellent in its quality even as high as 5% supplemental level. 3. The higher levels of supplementation were used the more sticky cooking products were obtained. Song-Pyun and wheat cake were palatable and lustrous in 2% supplementation level. 4. In drop cookie the higher levels of supplementation, the more crisp product was obtained, compared with other cookies. 5. Corn cake, thin rice gruel, rice gruel and potato Jeon-Byung were more excellent in their quality than potato Man-Doo and potato noodle. Corn cake, thin rice gruel and rice gruel were excellent even as high as 5% supplementation level. 6. In several cooking Porducts some seaweed-oder was perceived in case of 3% or more levels of supplementation. This may be much diminished by the use of proper condiments. D. Sanitary test It seems that there is no any heavy metals (Cd, Pb, As, Hg) problem in these seaweed Powders in case these Powders are used as supplements to any cereal flours E. Economical analysis The price of the seaweed powder is lower than those of other cereals and that may be more lowered when mass production of the seaweed powder is made in future. The supplement of the seaweed powder to any cereals is also economical with the criterion of animal growth rate. F. It is recommended that these seaweed powders should be developed and used as supplement to any cereal flours or used as other food material. By doing so, both saving of cereals and improvement of individual's nutrition will greatly be achieved. It is also recommended that the feeding experiment for men would be conducted in future.

  • PDF

영양강화 Rotifer와 효소활성 향상 Rotifer의 먹이효율 비교 (Comparison of Feed Efficiency Between Rotifers Enriched Lipid-contents to Enrichment and Enhanced Digestive Enzymes Activity to Starch)

  • 권오남;박흠기
    • 한국양식학회지
    • /
    • 제22권1호
    • /
    • pp.105-111
    • /
    • 2009
  • 본 연구는 rotifer가 가진 소화효소환성과 영양적인 측면에서 자어의 소화력을 평가하기 위한 실험을 하였다. 그래서 rotifer의 소화력을 증가시켜 주기 위해 배양수에 starch를 첨가하여 rotifer (starch-rotifer)의 소화효소 활성을 향상시켰으며 지질 영양강화 rotifer (CE-rotifer)와 비교하여 넙치자어를 이용하여 먹이효율 실험을 하였다. 이들 rotifer의 소화효소 (lipase 제외), 총 단백질, 필수아미노산 총량, 필수아미노산(methionin과 phenylalanine)에서 starch-rotifer가 높게 나타났다. 하지만 총지질, 지질 클래스(sterol 제외)및 DHA, EPA와 같은 지방산은 CE-rotifer에서 높게 나타났다. 그러나 sterol과 ST/TG 비는 starch-rotifer에서 유의적으로 높게 나타났다P<0.05). 이 두 가지 rotifer를 공급받은 넙치자어는 부화 후 6일까지 체장과 체중에서 $3.72{\sim}3.79\;mm$$32.9{\sim}37.8\;mg$/larva의 범위로 유의적인 차이가 없었다(P>0.05). 그러나 부화 후 12일째는 CE-넙치에서 starch-넙치가 보다 높은 $5.94{\pm}0.249\;mm$, $144.0{\pm}23.86\;mg$/larva 및 $26.2{\pm}2.13%$의 생존율을 보였다. 이들 두 rotifer를 공급받은 넙치자어의 가수분해 효소 활성은 부화 후 5일째 acidic -amylase, neutral -amylase, TG-lipase, lysozyme 및 acidic Phosphatase에서 starch-넙치에서 유의적으로 높게 조사되었으나, 부화 후 11일째는 CE-넙치의 neutral $\alpha$-amylase, three pretenses, two phosphatases에서 starch-넙치보다 유의적으로 높은 활성을 보였다. 결과적으로 넙치자어는 부화 후 6일까지 영양강화 rotifer를 공급하는 것보다 소화효소 활성을 향상시킨 먹이를 공급하는 것이 자어의 소화력 측면에서 유익하며, 이후 소화기관의 발달로 영양의 흡수가 원활해져서 영양강화 효과가 자어의 성장으로 나타났다고 판단된다. 따라서 이후 소화효소활성과 영양의 측면에서 부화 후 6일 이후에 대한 상세한 고찰이 필요할 것으로 판단된다.

Prevotella intermedia에서의 Hemin 결합 단백질 유전자의 분리 및 염기서열 분석 (MOLECULAR CLONING AND SEQUENCE ANALYSIS OF THE GENE FOR THE HEMIN-BINDING PROTEIN FROM Prevotella intermedia)

  • 김신;김성조
    • 대한소아치과학회지
    • /
    • 제33권2호
    • /
    • pp.304-310
    • /
    • 2006
  • 본 연구는 치주질환 주요 병인균주 중의 하나인 P. intermedia를 대상으로 하여, 이 균주에서의 hemin 결합 단백질 유전자를 분리하고 염기서열을 결정하기 위하여 수행되었다. 본 연구에서는 약 5,000개의 recombinant colony들을 스크리닝하여 hemin 결합 단백질 유전자를 포함하고 있는 것으로 여겨지는 1개의 클론(pHem1)을 확인하였다. Restriction enzyme mapping 결과 pHem1의 insert DNA의 크기는 약 2.5kb이었으며 P. intermedia chromosomal DNA 내에는 hemin 결합 단백질 유전자가 single copy로 존재하였고, transcript의 크기는 약 1.8kb이었다. 분리한 pHem1 유전자는 1개의 ORF를 가지고 있으며, ORF의 크기는 2,550bp로 약 850개의 아미노산 폴리펩타이드로 구성되어 있다. 또한, pHem1 유전자는 이미 밟혀진 다른 유전자들과 상동성을 보이지 않았다. 본 연구는 P. intermedia에서의 porphyrin생리 및 hemin 획득기전을 분자생물학적으로 규명하는데 있어 중요한 의의가 있으리라 사료된다. 향후 pHem1 유전자의 특성 분석 등이 수행되어야 할 것으로 여겨진다.

  • PDF