• 제목/요약/키워드: amino acid substitution

검색결과 170건 처리시간 0.026초

Structure-Antifungal Activity Relationships of Cecropin A-Magainin 2 and Cecropin A-Melittin Hybrid Peptides on Pathogenic Fungal Cells

  • Lee, Dong-Gun;Jin, Zhe-Zhu;Shin, Song-Yub;Kang, Joo-Hyun;Hahm, Kyung-Soo;Kim, Kil-Lyong
    • Journal of Microbiology and Biotechnology
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    • 제8권6호
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    • pp.595-600
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    • 1998
  • In order to investigate a relationship of the structure-antifungal and hemolytic activities between cecropin A(1-8)-magainin 2(1-12) and cecropin A(1-8)-melittin(1-12) hybrid peptides, several analogues with amino acid substitution at positions 10 (Ile) and 16 (Ser) were designed and synthesized. The increase of the hydrophobicity by substituting with Leu, Phe, and Trp at position 16 in cecropin A(1-8)-magainin 2(1-12) did not have a significant effect on antifungal activity but caused a remarkable increase in hemolytic activity. These results indicate that the hydrophobic property at position 16 of cecropin A(1-8)-magainin 2(1-12) is more correlated to hemolytic activity than to antifungal activity. Replacement with Pro at position 10 of cecropin A(1-8)- magainin 2(1-12) and cecropin A(1-8)-melittin (1-12) caused a remarkable decrease in a-helical contents in the 50% TFE solution and induced a reduction in lytic activity against Aspergillus flavus, and Aspergillus fumigatus. These results demonstrate that flexibility at the central hinge region is essential for lytic activity against fungal cells and $\alpha$-helicity of the peptides.

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마약길항제의 방출 제어형 제제 (제1보) : 생체분해성 polyphosphazenes의 합성과 나록손 이식제제의 제조 및 용출특성 (Controlled Release Dosage Form of Narcotic Antagonist(I): Synthesis of Biodegradable Polyphosphazenes and Preparation and Release Characteristics of Naloxone Implant)

  • 박주애;이승진;김형국;김길수
    • Journal of Pharmaceutical Investigation
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    • 제25권2호
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    • pp.109-116
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    • 1995
  • For the administration of narcotic antagonist with short half-life and low patient compliance, the sustained release system using biodegradable matrix is effective. Polyphosphazenes are of considerable interest as biodegradable matrix systems for controlled release of drugs. In this study, biodegradable polyphosphazenes available for the sustained release implantable device were synthesized, and their application was examined. Poly[dichlorophosphazene] was synthesized by solution polymerization method and confirmed with IR spectrum. Poly[bis(ethyl glycinate) phosphazene] and poly[ (diethyl glutamate)-co-(ethyl glycinate)phosphazene] were then produced by substitution of amino acid alkyl esters for chloride side groups. Using these polymers, the implantable devices of 1 mm thickness and $10{\times}10\;mm$ size containing naloxone hydrochloride were prepared and their release and degradation profiles were measured. In the case of poly[bis(ethyl glycinate)phosphazene] with swelling characteristics, degradation rate was slower than the release rate, showing that the release rate is partly dependent on the swelling rate. In contrast, the degradation rate of polyl[(diethyl glutamate)-co-(ethyl glycinate)phosphazene] matrix was identical with release rate of naloxone hydrochloride. On the basis of these results, it is expected that these polymers can be applied to sustained release implantable systems delivering narcotic antagonist.

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Expression of Human Papillomavirus Type 16, Prototype and Natural Variant E7 Proteins using Baculovirus Expression System

  • Han, Hee-Sung;Kee, Sun-Ho;Hwang, Soon-Bong;Kim, Hyung-Jun;Cho, Kyung-A;Kim, Yoon-Won;Cho, Min-Kee;Chang, Woo-Hyun
    • 대한바이러스학회지
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    • 제28권1호
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    • pp.53-62
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    • 1998
  • Human papillomavirus (HPV) 16, E7 proteins derived from the prototype (Bac73) and natural variant (Bac101) E7 open reading frame were produced in Sf9 insect cells. The variant E7 gene occurred naturally by substitution mutation at the position of 88 nucleotide, resulting serine instead of asparagine. Using E7 specific monoclonal antibody (VD6), both E7 proteins were identified in recombinant baculovirus infected SF9 cells. Radiolabelling and immunoprecipitation analysis revealed that both E7 proteins were phosphoproteins. Immunostaining result showed that E7 proteins were mainly localized in the cytoplasm. Nuclear form of E7 proteins was also detected after a sequential fractionation procedure for removing chromatin structure. Considering that the VD6 recognition site in E7 protein is located within 10 amino acid at the N-terminus, this region appears to be blocked by the nuclear component. Western blot analysis revealed that nuclear form was more abundant than cytoplasmic E7 proteins. Time course immunostaining showed that the primary location of E7 protein was the nucleus and exported to the cytoplasm as proteins were accumulated. These events occurred similarly in both Bac73 and Bac101 infected Sf9 cells, suggesting that these two proteins may have similar biological functions.

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Alternanthera mosaic virus - an alternative 'model' potexvirus of broad relevance

  • Hammond, John;Kim, Ik-Hyun;Lim, Hyoun-Sub
    • 농업과학연구
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    • 제44권2호
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    • pp.145-180
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    • 2017
  • Alternanthera mosaic virus (AltMV) is a member of the genus Potexvirus which has been known for less than twenty years, and has been detected in Australasia, Europe, North and South America, and Asia. The natural host range to date includes species in at least twenty-four taxonomically diverse plant families, with species in at least four other families known to be infected experimentally. AltMV has been shown to differ from Potato virus X (PVX), the type member of the genus Potexvirus, in a number of ways, including the subcellular localization of the Triple Gene Block 3 (TGB3) protein and apparent absence of interactions between TGB3 and TGB2. Differences between AltMV variants have allowed identification of viral determinants of pathogenicity, and identification of residues involved in interactions with host proteins. Infectious clones of AltMV differing significantly in symptom severity and efficiency of RNA silencing suppression have been produced, suitable either for high level protein expression (with efficient RNA silencing suppression) or for Virus-Induced Gene Silencing (VIGS; with weaker RNA silencing suppression), demonstrating a range of utility not available with most other plant viral vectors. The difference in silencing suppression efficiency was shown to be due to a single amino acid residue substitution in TGB1, and to differences in subcellular localization of TGB1 to the nucleus and nucleolus. The current state of knowledge of AltMV biology, including host range, strain differentiation, host interactions, and utility as a plant viral vector for both protein expression and VIGS are summarized.

Molecular dissection of OsSAD1 conferring salt-, ABA- and drought stresses in rice

  • Park, Yong Chan;Jang, Cheol Seong
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.149-149
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    • 2017
  • The RING (Really Interesting New Gene) finger proteins are known to play crucial roles in various abiotic stresses in plants. In this study, we report on RING finger E3 ligase, ${\underline{O}ryza}$ ${\underline{s}ativa}$ ${\underline{s}alt$-, ${\underline{A}BA}$- and ${\underline{d}rounght}$ stress-${\underline{i}nduced}$ RING finger ${\underline{p}}rotein{\underline{1}}$ gene (OsSAD1). In vitro ubiquitination assay demonstrated that unlike OsSAD1, a single amino acid substitution ($OsSAD1^{C168A}$) of the RING domain showed no E3 ligase activity, supporting the notion that the activity of most E3s is specified by a RING domain. Result of Yeast-Two hybridization, In vivo protein degradation assay supports that OsSAD1 interacting with 3 substrate, OsSNAC2, OsGRAS44 and OsPIRIN1, and mediates proteolysis of 3 substrates via the 26S proteasome pathway. Subcellular localizations of OsSAD1 while approximately 62% of transient signals were detected in cytosol, 38% of signals were showed nucleus. However, transiently expression of OsSAD1 was detected in cytosol 30% while as 70% of nucleus under 200 mM salt treated rice protoplasts. Results of bimolecular fluorescence complementation (BiFC) showed that two nucleus-localized proteins (OsSNAC2 and OsGRAS44) interacted with OsSAD1 in the both cytosol and nucleus. Heterogeneous overexpression of OsSAD1 Heterogeneous overexpresssion of OsSAD1 in Arabidopsis exhibited sensitive phenotypes with respect to Salt-, mannitol-responsive seed germination, seedling growth. In ABA conditions, OsSAD1 overexpression plants showed highly tolerance phenotypes, such as root length and stomatal closure. Our findings suggest that the OsSAD1 may play a negative regulator in salt stress response by modulating levels of its target proteins.

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Diverse mechanism on cadmium uptake among rice varieties

  • Lee, Sang Beom;Kim, Kyu Won;Kim, Gyeong Jin;Choi, Buung;Yoo, Ji Hyok;Oh, Kyeong Seok;Moon, Byeong Churl;Park, Yong-jin;Park, Sang Won
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.157-157
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    • 2017
  • In last study, Genome-Wide Association Studies (GWAS) was conducted for cadmium content of 295 rice varieties including 137 rice core set and 157 Korea breeding varieties collected from Kongju National University. The results showed that 9 varieties had SNP allele and amino acid substitution in exon of chromosome 1. This study was aim to understanding mechanism of cadmium uptake to confirm correlation of cadmium and other mineral nutrients (Cu, Mn, Fe) among 9 rice varieties. Nine varieties were planted on polluted soil of mine in Korea and cadmium content in root, stem, leaf and it's brown rice was analyzed by ICP-MS (Inductively Coupled Plasma Mass spectrometer, Agilent 7700E, US). Results of this study showed that mechanism for cadmium uptake and accumulation was diversity among varieties. Chin-nong and Ho-nong contained higher levels of cadmium in root, but contained relatively lower levels cadmium in brown rice than other varieties. Cheong-nam, Nam-pyeong, Gan-cheok, Suan absorbed high levels of cadmium through root and then accumulated high cadmium to brown rice. Meanwhile, Yeong-deok and Su-kwang absorbed lower cadmium in root, but high cadmium was accumulated in brown rice. Correlations between cadmium and other mineral nutrients (Cu, Mn, Fe) were analyzed by using SPSS statistics 20. The contents of iron in leaf had minus correlation (p<0.05) with cooper and cadmium in root, cadmium in brown rice. Therefore understanding of cadmium uptake mechanism among varieties will be used to basic data for further breeding and phytoremediation.

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Patterns of rpoC Mutations in Drug-Resistant Mycobacterium tuberculosis Isolated from Patients in South Korea

  • Yun, Yeo Jun;Lee, Jong Seok;Yoo, Je Chul;Cho, Eunjin;Park, Dahee;Kook, Yoon-Hoh;Lee, Keun Hwa
    • Tuberculosis and Respiratory Diseases
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    • 제81권3호
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    • pp.222-227
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    • 2018
  • Background: Rifampicin (RFP) is one of the principal first-line drugs used in combination chemotherapies against Mycobacterium tuberculosis, and its use has greatly shortened the duration of chemotherapy for the successful treatment of drug-susceptible tuberculosis. Compensatory mutations have been identified in rpoC that restore the fitness of RFP-resistant M. tuberculosis strains with mutations in rpoB. To investigate rpoC mutation patterns, we analyzed 93 clinical M. tuberculosis isolates from patients in South Korea. Methods: Drug-resistant mycobacterial isolates were cultured to determine their susceptibility to anti-tubercular agents. Mutations in rpoC were identified by sequencing and compared with the relevant wild-type DNA sequence. Results: In total, 93 M. tuberculosis clinical isolates were successfully cultured and tested for drug susceptibilities. They included 75 drug-resistant tuberculosis species, of which 66 were RFP-resistant strains. rpoC mutations were found in 24 of the 66 RFP-resistant isolates (36.4%). Fifteen different types of mutations, including single mutations (22/24, 91.7%) and multiple mutations (2/24, 8.3%), were identified, and 12 of these mutations are reported for the first time in this study. The most frequent mutation involved a substitution at codon 452 (nt 1356) resulting in amino acid change F452L. Conclusion: Fifteen different types of mutations were identified and were predominantly single-nucleotide substitutions (91.7%). Mutations were found only in dual isoniazid- and RFP-resistant isolates of M. tuberculosis. No mutations were identified in any of the drug-susceptible strains.

Effect of Butyrophilin Gene Polymorphism on Milk Quality Traits in Crossbred Cattle

  • Bhattacharya, T.K.;Misra, S.S.;Sheikh, Feroz D.;Sukla, Soumi;Kumar, Pushpendra;Sharma, Arjava
    • Asian-Australasian Journal of Animal Sciences
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    • 제19권7호
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    • pp.922-926
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    • 2006
  • A genetic polymorphism study on butyrophilin gene was carried out to explore variability of this gene and to estimate effects of such variability on milk quality traits in crossbred cattle. Polymorphism was unraveled by conducting Hae III PCR-RFLP of this gene. Three genotypes such as AA, BB and AB and two alleles namely A and B were observed in crossbred population. The frequencies of genotypes and alleles were 0.78, 0.17 and 0.04 for AA, AB and BB genotypes, respectively, and 0.87 and 0.13 for A and B alleles, respectively. The nucleotides, which have been substituted from allele A to B, were observed as C to G ($71^{st}$ nucleotide), C to T ($86^{th}$ nucleotide), A to T ($217^{th}$ nucleotide), G to A ($258^{th}$ nucleotide), A to C ($371^{st}$ nucleotide) and C to T ($377^{th}$ nucleotide). The nucleotide substitutions at $71^{st}$, $86^{th}$ and $377^{th}$ position of the fragment were found as silent mutations whereas nucleotide changes at $217^{th}$, $258^{th}$ and $371^{st}$ positions were detected as substitution of amino acid lysine with arginine, valine with isoleucine, and leucine with proline from allele A to B. The genotypes had significant effects ($p{\leq}0.05$) on total milk solid%, fat%, SNF%, while showing nonsignificant impact on total protein%. AA genotype produced highest average yield for all the traits.

Prediction Value of XRCC 1 Gene Polymorphism on the Survival of Ovarian Cancer Treated by Adjuvant Chemotherapy

  • Miao, Jin;Zhang, Xian;Tang, Qiong-Lan;Wang, Xiao-Yu;Kai, Li
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권10호
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    • pp.5007-5010
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    • 2012
  • Objective: We conducted a prospective study to test the association between three amino acid substitution polymorphismic variants of DNA repair genes, XRCC1 (Arg194Trp), XRCC1(Arg280His) and XRCC1 (Arg399Gln), and clinical outcome of ovarian cancer patients undergoing adjuvant chemotherapy. Methods: 195 patients with primary advanced ovarian cancer and treated by adjuvant chemotherapy were included in our study. All were followed-up from Jan. 2007 to Jan. 2012. Genotyping of XRCC1 polymorphisms was conducted by TaqMan Gene Expression assays. Results: The XRCC1 194 Trp/Trp genotype conferred a significant risk of death from ovarian cancer when compared with Arg/Arg (HR=1.56, 95%CI=1.04-3.15). Similarly, those carrying the XRCC1 399 Gln/Gln genotype had a increased risk of death as compared to the XRCC1 399Arg/Arg genotype with an HR (95% CI) of 1.98 (1.09-3.93). Conclusion: This study is the first to provide evidence that XRCC1 gene polymorphisms would well be useful as surrogate markers of clinical outcome in ovarian cancer cases undergoing adjuvant chemotherapy.

해수 사육 무지개송어(Oncorhynchus mykiss)에서 분리된 Vibrio anguillarum의 특성 분석 (Characteristics of Vibrio anguillarum Isolated from Seawater Cultured Rainbow Trout Oncorhynchus mykiss in Korea)

  • 천혜진;김위식;조미영;정승희;한현자
    • 한국수산과학회지
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    • 제51권3호
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    • pp.254-261
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    • 2018
  • From 2014 to 2017, mortalities of seawater-cultured rainbow trout Oncorhynchus mykiss, were observed in the Goheung and Jeju areas of Korea, with Vibrio anguillarum (seven strains: RT1, 2, 3, 4, 5, 6, and 7) identified as the etiological agent. The phenotypic (based on API 20NE, API ZYM, and E-test kits), serotypic (slide agglutination tests with O1, O2, O3, O4, and O7 antisera), and genotypic (16S rRNA and ompU sequencing) characteristics of the seven RT strains were analyzed and compared to those of seven additional V. anguillarum stains (SF, isolated from sweet fish; FM, isolated from flathead mullet; ATCC43305; ATCC43311; ATCC43307; ATCC43308; and KCTC2711). The phenotypes of the RT strains showed variance, while the slide agglutination tests of the RT1-7, SF, and FM strains all showed positive reactions with serotype O1 antiserum. The 16S rRNA and ompU sequences of the RT1-7, SF, and FM strains were affiliated with V. anguillarum ATCC43305 (Serotype O1), but the ompU sequence of the SF strain differed from those of the RT1-7, FM, and ATCC43311 strains, including one amino acid substitution. We thus confirmed that serotype O1 V. anguillarum, with multiple phenotypes, continues to infect seawater-cultured rainbow trout in Korea.