• 제목/요약/키워드: asparagine

검색결과 343건 처리시간 0.027초

Evaluation of Nonanchored Inter Simple Sequence Repeat (ISSR) Marker to Detect DNA Damage in Common Bean (Phaseolus vulgaris L.) Exposed to Acrylamide

  • Enan, Mohamed R.
    • Journal of Forest and Environmental Science
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    • 제24권2호
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    • pp.61-68
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    • 2008
  • Acrylamide is present as a contaminant in heated food products, predominantly from the precursor asparagine. Nonanchored inter simple sequence repeats (ISSRs) are arbitrary multiloci markers produced by PCR amplification with a microsatellite primer. In order to assess the feasibility of microsatellite primers as markers for DNA damage, the study was conducted on common bean (Phaseolus vulgaris L.) exposed to different concentrations of acrylamide. Polymorphisms were abundant among plant samples treated with acrylamide in comparison to control (untreated one) tested with 4- tri-nucleotide, 2 tetra-nucleotide, and 3- dinucelotide primers. The primer (CCG)4 was the best tested primer to generate polymorphism between the DNA of plants treated or not by acrylamide. Polymorphisms became evident as the presence and absence of DNA fragments in treated samples compared with the untreated one. The highest number of DNA variation on ISSR patterns was observed at the micromollar concentrations of acrylamide. Acrylamide was able to induce DNA damage in non concentration-dependent manner with effectiveness at micromollar concentrations. This study demonstrated that ISSR markers can be highly reliable for identification of DNA damage induced by acrylamide.

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면역증강물질을 생산하는 해양미생물의 분리 및 동정 (Isolation and Identification of a Marine Bacterium Producing an Immunostimulant)

  • 최혜정;정명주;정영기
    • 한국식품영양과학회지
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    • 제29권6호
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    • pp.1145-1150
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    • 2000
  • 면역증강물질을 생산하는 균주를 해수로부터 분리하여 동정한 결과 크림색의 둥근 점질성의 집략을 나타내었으며, Gram 음성의 간산형이고, 미약한 운동성을 가지며 catalase 양성과 oxidase 음성 반응을 보였다. 균주를 6시간 , 20시간, 72시간, 및 144시간 뱅양하여 전자 현미경사에서 관찰한 결과 20시간 배양한 영양세포는 1.25~0.6$\times$0.6$\mu\textrm{m}$ 크기의 간균 형태를 갖추었으며 시간이 흐를수록 세포내 관립의 밀도가 증가하면서 세포형태가 다형태성으로 변하였다. 세포내 과립의 존재를 확인하기 위해 sudan black B로 염색한 결과 양성으로 polyhy-droxy butyrate로 예상되었다. 생육을 위한 최적 온도는 3$0^{\circ}C$, pH는 3.0~10.0이었으며, 호기성균이었다. D-Glu-cose, D-mannose, D-mannitiol. insitol, maltose 등의 당과 L-asparagine, L-glutamate 등의 아미노산을 이용하였고 특시, O/F test에서 glucose와 maltose를 산화 하였다. 이상과 같은 결과로 해양세균 유래인 Pseudo-mallei group의 Burkholderia 속으로 확인되었음로 본 균주를 Burkholderia sp. IS-203으로 명명하였다.

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곰보버섯 균사체의 배양특성

  • 차월석;이동병;정길록
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2003년도 생물공학의 동향(XII)
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    • pp.175-179
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    • 2003
  • 농촌진흥청, 사천성, 산동성의 곰보버섯 균주의 최적 배양조건을 찾기 위해 배지, 탄소원, 질소원을 변화시켜 살펴본 결과는 다음과 같다. 배지에서 RDA와 SCP는 YSB 배지에서 각각 0.250 및 0.350 g을 보였으며, SDP는 Czpek 배지 0.294 g의 최대 생산량을 보였으며, 탄소원에서 RDA은 최대 균사체 성장이 maltose에 의해 0.272 g, SCP의 경우는 fluctose에 의해 0.420 g, SDP는 mannitol에 의해 0.385 g의 생산량을 보였다. 질소원에서 RDA은 최대 균사체 성장이 Yeast extract와 $NH_4Cl$에 의해 0.325 g, SCP의 경우에는 Yeast extract에 의해 0.412 g, SDP의 경우에는 Asparagine, $NH_4Cl$에 의해 0.435 g의 생산량을 보였다. 또한 최적 온도는 $25^{\circ}C$였으며, PH는 5.5 - 6.5 사이로 나타났다. 버섯 및 질소원에 따라 $NH_4Cl$을 추가했을 때 성장된 균사체의 양은 다르게 나타나 이에 대한 연구는 추가적으로 진행되어야 할 것으로 사료된다.

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Effect of Deglycosylation on the Aminopeptidase Isolated from Aspergillus flavus

  • Cho, Mi-Sook;Chung, Hye-Shin
    • BMB Reports
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    • 제32권3호
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    • pp.317-319
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    • 1999
  • A leucine aminopeptidase has been isolated from the culture medium of the soil fungus, Aspergillus flavus. The enzyme was found to be a glycoprotein, as judged by electrophoresis analysis and the subsequent staining by the periodic acid-Schiff's reagent. Carbohydrate moieties could be cleaved by N-glycosidase, but not by O-glycosidase, indicating that the glucans are linked to the asparagine residue in the protein. Removal of N-glucans was observed without prior denaturation of the protein, implying that the N-glycosidic linkage is exposed and accessible to glycosidase. When the activity of native or deglycosylated enzyme was measured in the presence of various metal ions, removal of carbohydrates increased the aminopeptidase activity of the enzyme.

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Asparagine-473 Residue Is Important to the Efficient Function of Human Dihydrolipoamide Dehydrogenase

  • Kim, Hak-Jung
    • BMB Reports
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    • 제38권2호
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    • pp.248-252
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    • 2005
  • Dihydrolipoamide dehydrogenase (E3) catalyzes the reoxidation of dihydrolipoyl moiety of the acyltransferase components of three $\alpha$-keto acid dehydrogenase complexes and of the hydrogen-carrier protein of the glycine cleavage system. His-457 of Pseudomonas putida E3 is suggested to interact with the hydroxyl group of Tyr-18 of the other subunit and with Glu-446, a component in the last helical structure. To examine the importance of the suggested interactions in human E3 function, the corresponding residue of human E3, Asn-473, was substituted to Leu using site-directed mutagenesis. The E3 mutant was expressed in Escherichia coli and highly purified using an affinity column. Its E3 activity was decreased about 37-fold, indicating that Asn-473 residue was important to the efficient catalytic function of human E3. Its slightly altered spectroscopic properties implied that small conformational changes could occur in the E3 mutant.

Thiobacillus concretivorus의 분리 및 동정에 관한 연구 (Studies on isolation and identification of thiobacillus concretivorus)

  • 하영칠;차승희;안승구
    • 미생물학회지
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    • 제10권4호
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    • pp.155-166
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    • 1972
  • With respect to a bacterium isolated some of the similarities and differences previously indicated between Thiobacillus thiooxidans and Thiobacillus concretivorus wee confirmed and the bacteria also provided considerable diferences compared to the two species in some repects. Severe precipitation of sulfur occurred in colonies and in liquid media of the organism isolated. The organism isolated utilized nitrate and asparagine as well as ammonium sulfate as a sole nitrogen source and grew well without being nearly inhibited by citrate and malate. This organism also showed the resistance to heats and external physical stimulations. Owing to some characters decribed above and the reports proposed, the organism isolated could be concluded to be Thiobacillus concretivorus and it was suggested that Thiobacillus concretivorus might be an apparently different species from Thiobacillus thiooxidans.

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Farnesyl protein transferase 방해제 연구를 통한 항암제의 개발

  • 이상규;박세연;백영진;최희정;양철학
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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    • pp.180-180
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    • 1994
  • Farnesyl protein transferase는 Ras precursor의 C-terminal에 있는 cystein residue에 farnesyl group을 결합시키는 효소다. 이 효소를 bovine testis에서 30-50% ammonium sulfate fractionation, DEAE-sephacel ion exchange, Sephacryl s-300 gel filtration, hexapeptide(KKCVIM) affinity chromatography를 통해 30000배로 분리하였다. 분리된 효소는 gel filtration시 약 100kDa으로, SDS-polyacrylamide 전기영동시 50kDa의 인접한 두 bands로 나타났고 이것은 $\alpha$, $\beta$ subunits으로 생각되었다. $\alpha$ subunit을 encoding하는 RAM2 유전자를 site directed mutagenesis로 145번의 histidine을 aspartate로, 140번의 aspartate를 asparagine 으로 바꾸었더니 optimal pH와 $K_{m}$ 값이 변했다. Diethyl pyrocarbonate로 histidine residues를 chemical modification시켰을때 효소의 활성이 저하되었다. 145번 histidine이 aspartate로 바뀐 돌연변이효소에서 비교적 느리게 활성이 저하되므로 145번 histidine이 이 효소의 active site에 있을것으로 추측된다.

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향균류공업에서의 후생물학적 품질관리 (Microbiological Quality Control in the Cosmetic Industry)

  • 정교민;홍순우
    • 미생물학회지
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    • 제15권3호
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    • pp.131-138
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    • 1977
  • The effects of various nitrogen soruces on the expression of nif gene were investigated using nif-lac fusants of Klebsiella pneumoniae. K. pneumoniae UK 2979 was infected with Mudl lysate prepared by heat induction of K. pneumoniae UK 4482. About 80 nif-lac fusants were greatly repressed. Amino acids, such as serine, glutamine and asparagine, were found to support the growth of K. pneumoniae M5al quite well, and showed a repressive effect on .betha.-galactosidase activities of nif-lac fusants LX-9 and LX-22 in NFHM. Glutamic acid, histidine and arginine rendered poor growth but high activities of .betha.-galactosidase. Good cell growth and high enzyme activity were observed when complex nitrogen sources, such as casitone, proteose pepone, were employed. .betha.-Galactosidase activities of LX-9 and LX-22 in nitrogen free minimal medium increased sharply within first 4 hours.

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다수 배지의 사용에 따른 방선균의 중복 분리빈도 (Reisolation Frequency of Soil Actinomycetes on Multiple Isolation Media)

  • 김창진;이강현;아끼라 시마즈;유익동
    • 한국미생물·생명공학회지
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    • 제22권3호
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    • pp.329-331
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    • 1994
  • For effective screening research, to isolate many different strains not duplicated would be essential. Three kinds of media were used for selective isolation of actinomycetes to test the reisolation frequency. Sixty species were isolated on Bennet's agar, 47 were on glycerol-asparagine agar and 77 were on humic acid-vitamin agar from 10 domestic soil samples. All of these isolates were identified to the genus level based on morphological characters and examined the sameness on each medium. The reisolation frequency between two different media was 10% or so(8.3~16.7%) and among three different media was 25% or so(22.1~27.7%).

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바지락젓의 유리(遊離)아미노산(酸) (Changes in the Free Amino Acids During the Fermentation of Clam, Tapes japonica)

  • 김행자
    • Journal of Nutrition and Health
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    • 제16권1호
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    • pp.34-40
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    • 1983
  • Clam, Tapes japonica, has been widely used and occupies an important position in the markets. More than thirty kinds of fermented fish and shellfish are presently available in the markets in korea. This study was attempted to establish the basic data for evaluating the taste compounds of the clam. The free amino acids as taste compounds during the fermentation of the clam, Tapes japonica, were analyzed by an amino acid autoanalyzer. Alanine (17.0%), glycine (15.5%), taurine (13.9%) were high in amount in the fresh clam and then glutamic acid, arginine, tyrosine, asparagine, lysine, threonine, serine and leucine were the next in order. Such amino acids as methionine, phenylalanine, histidine and cystine were low in amounts. The total free amino acid nitrogen in the fresh clam was 45.5% of its extract nitrogen. During the fermentation of the clam, the kinds of the free amino acids were the same with the fresh samples although the amounts were changed. It is believed that glutamic acid, aspartic acid, glycine, alanine, lysine, and leucine may play an important role as the taste compounds in the fermented clam.

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