• 제목/요약/키워드: ${\alpha}$-amino acids

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Influence of the Hydrophobic Amino Acids in the N- and C-Terminal Regions of Pleurocidin on Antifungal Activity

  • Lee, June-Young;Lee, Dong-Gun
    • Journal of Microbiology and Biotechnology
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    • 제20권8호
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    • pp.1192-1195
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    • 2010
  • To investigate the influence of the N- or C-terminal regions of pleurocidin (Ple) peptide on antifungal activity, four analogs partially truncated in the N- or C-terminal regions were designed and synthesized. Circular dichroism (CD) spectroscopy demonstrated that all the analogs maintained an alpha-helical structure. The antifungal susceptibility testing also showed that the analogs exhibited antifungal activities against human fungal pathogens, without hemolytic effects against human erythrocytes. The result further indicated that the analogs had discrepant antifungal activities [Ple>Ple (1-22)>Ple (4-25)>Ple (1- 19)>Ple (7-25)] and that N-terminal deletion affected the activities much more than C-terminal deletion. Hydrophobicity [Ple>Ple (1-22)>Ple (4-25)>Ple (1-19)> Ple (7-25)] was thought to have been one of the consistent factors that influenced these activity patterns, rather than the other primary factors like the helicity [Ple>Ple (4-25) >Ple (1-22)>Ple (1-19)>Ple (7-25)] or the net charge [Ple=Ple (4-25)=Ple (7-25)>Ple (1-22)=Ple (1-19)] of the peptides. In conclusion, the hydrophobic amino acids in the N-terminal region of Ple is more crucial for antifungal activity than those in the C-terminal region.

One-Step Enzymatic Synthesis of Blue Pigments from Geniposide for Fabric Dyeing

  • Cho, Y.J.;Kim, S.Y.;Kim, J.;Choe, E.K.;Kim, S.I.;Shin, H.J.
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제11권3호
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    • pp.230-234
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    • 2006
  • In this study, we describe a one-step chemoenzymatic reaction for the production of natural blue pigments, in which the geniposide from Gardenia extracts is transformed by glycosidases to genipin. Genipin is then allowed to react with amino acids, thereby generating a natural blue pigment. The ${\beta}-glycosidases$, most notably Isolase (a variant of ${\beta}-glucanase$), recombinant ${\beta}-glycosidases$, Cellulase T, and amylases, were shown to hydrolyze geniposide to produce the desired pigments, whereas the ${\alpha}-glycosidases$ did not. Among the 20 tested amino acids, glycine and tyrosine were associated with the highest dye production yields. The optimal molar ratio of geniposide to glycine, two reactants relevant to pigment production, was unity The natural blue pigments produced in this study were used to dye cotton, silk, and wool. The color yields of the pigments were determined to be significantly higher than those of other natural dyes. Furthermore, the color fastness properties of these dyes were fairly good, even in the absence of mordant.

Anti-adipogenic Effect of Hydrolysate Silk Fibroin in 3T3-L1 Cells

  • Chon, Jeong-Woo;Lee, Kwang-Gill;Park, Yoo-Kyoung;Park, Kyung-Ho;Yeo, Joo-Hong
    • International Journal of Industrial Entomology and Biomaterials
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    • 제21권2호
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    • pp.169-174
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    • 2010
  • Hydrolysate silk fibroin (HSF) is a fibrous protein composed of parallel $\beta$-structures and is made from pure silk elements including 18 amino acids, with glycine, alanine, and serine comprising of over 80% of the amino acids. Numerous studies have documented a range of effects of HSF, including moisturizing, antioxidant activity, nervous system disorders, and many more. We investigated whether HSF has anti-obesity effects in vitro. The effects of HSF inhibition on lipid accumulation and acceleration of lipid degradation in 3T3-L1 cells were studied. Treatment of 3T3-L1 cells with HSF caused significant inhibition of cell viability, an increase in glycerol release, and a decreased in adipocyte differentiation. Moreover HSF stimulated downregulated of adipogenic enzyme expressions (PPAR${\gamma}$ and C/EBP${\alpha}$) and up-regulated of fatty oxidation enzyme expressions (CPT-1 and UCP-2). Based on these results, hydrolysate silk fibroin can be suggested as a potential therapeutic substance as part of a prevention or treatment strategy for obesity.

Molecular Cloning and Characterization of a New C-type Lysozyme Gene from Yak Mammary Tissue

  • Jiang, Ming Feng;Hu, Ming Jun;Ren, Hong Hui;Wang, Li
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권12호
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    • pp.1774-1783
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    • 2015
  • Milk lysozyme is the ubiquitous enzyme in milk of mammals. In this study, the cDNA sequence of a new chicken-type (c-type) milk lysozyme gene (YML), was cloned from yak mammary gland tissue. A 444 bp open reading frames, which encodes 148 amino acids (16.54 kDa) with a signal peptide of 18 amino acids, was sequenced. Further analysis indicated that the nucleic acid and amino acid sequences identities between yak and cow milk lysozyme were 89.04% and 80.41%, respectively. Recombinant yak milk lysozyme (rYML) was produced by Escherichia coli BL21 and Pichia pastoris X33. The highest lysozyme activity was detected for heterologous protein rYML5 (M = 1,864.24 U/mg, SD = 25.75) which was expressed in P. pastoris with expression vector $pPICZ{\alpha}A$ and it clearly inhibited growth of Staphylococcus aureus. Result of the YML gene expression using quantitative polymerase chain reaction showed that the YML gene was up-regulated to maximum at 30 day postpartum, that is, comparatively high YML can be found in initial milk production. The phylogenetic tree indicated that the amino acid sequence was similar to cow kidney lysozyme, which implied that the YML may have diverged from a different ancestor gene such as cow mammary glands. In our study, we suggest that YML be a new c-type lysozyme expressed in yak mammary glands that plays a role as host immunity.

유카(Yucca shidigera)추출물의 첨가가 Bacillus subtilis p01을 이용한 청국장의 품질 특성에 미치는 영향 (Effect of Yucca (Yucca shidigera) Extract on Quality Characteristics of Chungkookjang using Bacillus subtilis p01)

  • 인재평;이시경
    • Applied Biological Chemistry
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    • 제47권2호
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    • pp.176-181
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    • 2004
  • Bacillus subtilis p01 균주를 사용한 청국장 제조 시 유카 추출물의 첨가가 청국장의 숙성중 품질 특성에 미치는 영향을 검토하고자 청국장 숙성 과정중의 아미노태 질소, 암모니아태 질소, amylase 활성, pretense 활성, 유기산 성분의 변화, 향기성분의 변화를 조사하였다. 청국장의 숙성 중 아미노태질소 함량은 유카 첨가구에서 증가 하였으며, 암모니아태 질소는 유카 첨가구에서 감소하였다. Amylase 활성은 유카 첨가구들이 대조구와 비교 시 높게 나타났으며, 유카 추출물을 0.5 mg/g 첨가 시 효소활성이 가장 높았다. Pretense 활성 역시 유카 추출물 첨가구가 무첨가구보다 다소 높게 나타났다. 유기산은 유카 첨가구들에서 citric acid, acetic acid, malic acid가 검출되었고, 2,5-Dimethylpyrazine이 증가하였고, 불쾌취로 작용되는 cis-3-hexane이 숙성 기간 중 감소함을 보였다.

효모에서 활성형의 곤충유래 항균펩티드 defensin의 발현 (Expression of Biologically Active Insect-Derived Antibacterial Peptide, Defensin, in Yeast)

  • 강대욱;안순철;김민수;안종석
    • 생명과학회지
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    • 제12권4호
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    • pp.477-482
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    • 2002
  • 효모 glucoamylase의 promoter와 분비신호서열 그리고 MF$\alpha$1의 prosequence를 이용하여 곤충 defensin을 S. cerevisiae 2805에서 항균활성을 보유한 형태로 발현 및 분비하는데 성공하였다. 발현된 defensin의 대부분이 세포 외로 분비되어 거의 모든 항균활성이 배양 상등액에 존재하였다. 이것은 S. cerevisiae에서 발현된 defensin이 glucoamylase의 분비신호서열과 MF$\alpha$1의 prosequenre에 의해 효율적으로 processing되어 분비됨을 시사한다. Defensin의 다른 미생물에 대한 항균활성을 조사한 결과 병원균인 St. aureus와 L. monocytogenes에 대해서도 항균활성이 존재하였다.

cDNA Cloning, Sequence Analysis and Molecular Modeling of a New Peptide from the Scorpion Buthotus saulcyi Venom

  • Nikkhah, Maryam;Naderi-Manesh, Hossein;Taghdir, Majid;Talebzadeh, Mehdi;Sadeghi-Zadeh, Majid;Schaller, Janatan;Sarbolouki, Mohamad N.
    • BMB Reports
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    • 제39권3호
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    • pp.284-291
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    • 2006
  • In this study, the cDNA of a new peptide from the venom of the scorpion, Buthotus saulcyi, was cloned and sequenced. It codes for a 64 residues peptide (Bsaul1) which shares high sequence similarity with depressant insect toxins of scorpions. The differences between them mainly appear in the loop1 which connects the $\beta$-strand1 to the $\alpha$-helix and seems to be functionally important in long chain scorpion neurotoxins. This loop is three amino acids longer in Bsaul1 compared to other depressant toxins. A comparative amino acid sequence analysis done on Bsaul1 and some of $\alpha$-, $\beta$-, excitatory and depressant toxins of scorpions showed that Bsaul1 contains all the residues which are highly conserved among long chain scorpion neurotoxins. Structural model of Bsaul1 was generated using Ts1 (a $\beta$-toxin that competes with the depressant insect toxins for binding to $Na^+$ channels) as template. According to the molecular model of Bsaul1, the folding of the polypeptide chain is being composed of an anti-parallel three-stranded $\beta$-sheet and a stretch of $\alpha$-helix, tightly bound by a set of four disulfide bridges. A striking similarity in the spatial arrangement of some critical residues was shown by superposition of the backbone conformation of Bsaul1 and Ts1.

Identification of Two Novel BCKDHB Mutations in Korean Siblings with Maple Syrup Urine Disease Showing Mild Clinical Presentation

  • Ko, Jung Min;Shin, Choong Ho;Yang, Sei Won;Cheong, Hae Il;Song, Junghan
    • Journal of Genetic Medicine
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    • 제11권1호
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    • pp.22-26
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    • 2014
  • Maple syrup urine disease (MSUD) is a disorder that involves the metabolism of branched chain amino acids, arising from a defect in branched-chain ${\alpha}$-keto acid dehydrogenase complex. Mutations have been identified in the BCKDHA, BCKDHB, or DBT genes, which encode different subunits of the BCKDH complex. Although encephalopathy and progressive neurodegeneration are its major manifestations, the severity of the disease may range from the severe classic type to milder intermediate variants. We report two Korean siblings with the milder intermediate MSUD who were diagnosed with MSUD by a combination of newborn screening tests using tandem mass spectrometry and family genetic screening for MSUD. At diagnosis, the patients' plasma levels were elevated for leucine, isoleucine, valine, and alloisoleucine, and branched-chain ${\alpha}$-keto acids and branched-chain ${\alpha}$-hydroxy acids were detected in their urine. BCKDHA, BCKDHB, and DBT analysis was performed, and two novel mutations were identified in BCKDHB. Our patients were thought to have the milder intermediate variant of MSUD, rather than the classic form. Although MSUD is a typical metabolic disease with poor prognosis, better outcomes can be expected if early diagnosis and prompt management are provided, particularly for milder forms of the disease.

INFLUENCE OF AMINO ACID SUPPLEMENTS TO A STRAW-MAIZE-BASED UREA DIET ON DUODENAL DIGESTA FLOW AND DIGESTION IN SHEEP

  • Fujimaki, T.;Kobayashi, Y.;Wakita, M.;Hoshino, S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제7권1호
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    • pp.137-145
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    • 1994
  • Amino acid (AA) substituted diets had no influence on rumen levels of total volatile fatty acids (VFA), ammonia and ${\alpha}$-amino-N, but tended to increase molar proportions of isovalerate and counts of total viable AA utilizing and celluloytic bacteria in the rumen as compared with the control urea diet. The AA diets did not affect daily flow to the duodenum of dry matter (DM), organic mater (OM) and acid detergent fibre (ADF), and rumen digestibility of these nutrients. However, the AA diets, in particular the 10 essential AA (EAA) diet improved total digestibility of DM, OM and ADF by decreasing faecal output of these fractions. Although N flow to the duodenum and N retention were not affected with the dietary treatments, duodenal bacterial flow appeared to increase by the AA diets when it was estimated by means of 2,6-diaminopimelic acid (DAP) and nucleic acid-purine bases (PB) as markers. The results suggest that AA supplements to a urea diet could improve feed utilization by stimulating microbial activity and proliferation in the rumen but and increased microbial activity per se is not necessarily associated with improvement of feed conversion.

An ESR Study of Amino Acid and Protein Free Radicals in Solution. Part IV. An ESR study of Gamma-Irradiated Amino Acids in Frozen Aqueous Solutions.

  • Sun-Joo Hong;D. E. Holmes;L. H. Piette.
    • 대한화학회지
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    • 제15권5호
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    • pp.256-265
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    • 1971
  • An ESR study has been made on free radicals produced in frozen aqueous solutions (ices) of glycine, DL-${\alpha}$-alanine, DL-serine, L-cysteine, DL-leucine and DL-isoleucine by gamma-irradiation at dry ice temperature. All free radicals induced were decayed concomitant to the successive annealing but the radical species which is believed to be dominant seems to be stable even near the melting point of the ice. These dominant species were found to be identical to those resulted from direct action of radiation in the solid at room temperature. Small but significant changes in the spectra of glycine and DL-${\alpha}$-alanine were observed by varying the microwave power. These results seem to support the view that the spectra obtained were composite consisting of more than two different resonances having different power saturation characteristics. The relative contribution of unidentified resonances to the composite spectra was greater for solutions of low concentration. These resonances are assumed to be induced by indirect effects, mainly hydrogen abstraction by radiation produced hydroxyl radicals and also C-N bond cleavage by hydrated electrons.

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