• Title/Summary/Keyword: Sequence selectivity

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Sequence Selectivity of DNA Alkylation by Adozelesin and Carzelesin

  • Yoon, Jung-Hoon;Lee, Chong-Soon
    • Archives of Pharmacal Research
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    • v.21 no.4
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    • pp.385-390
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    • 1998
  • Adozelesin and carzelesin are synthetic analogues of the extremely potent antitumor antibiotic CC-1065, which alkylates N3 of adenine in a consensus sequence $5^1$-(A/T)(A/T)$A^*$ ($A^*$ is the site of alkylation). We have investigated the DNA sequence selectivity of adozelesin and carzelesin by thermally ind ced DNA strand cleavage assay using radiolabeled restriction DNA fragments. An analysis of alkylation patterns shows that the consensus sequences for carzelesin and adozelesin have been found to be $5^1$-(A/T)(A/T)$A^*$ and $5^1$-(A/F)(G/C)(A/T)$A^*$. A new consensus sequence, $5^1$-(A/T)(A/T)$CA^*$, has been observed to display an additional alkylation site for adozelesin but not for carzelesin. These results indicate that the pattern of sequence selectivity induced by carzelesin is similar but not identical to those induced by adozelosin.

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Histogram-based Selectivity Estimation Method in Spatio-Temporal Databases (시공간 데이터베이스를 위한 히스토그램 기반 선택도 추정 기법)

  • Lee Jong-Yun;Shin Byoung-Cheol
    • The KIPS Transactions:PartD
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    • v.12D no.1 s.97
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    • pp.43-50
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    • 2005
  • The Processing domains of spatio-temporal databases are divided into time-series databases for moving objects and sequence databases for discrete historical objects. Recently the selectivity estimation techniques for query optimization in spatio-temporal databases have been studied, but focused on query optimization in time-series databases. There wat no previous work on the selectivity estimation techniques for sequence databates as well. Therefore, we construct T-Minskew histogram for query optimization In sequence databases and propose a selectivity estimation method using the T-Minskew histogram. Furthermore we propose an effective histogram maintenance technique for food performance of the histogram.

Selectivity Estimation for Multidimensional Sequence Data in Spatio-Temporal Databases (시공간 데이타베이스에서 다차원 시퀀스 데이타의 선택도추정)

  • Shin, Byoung-Cheol;Lee, Jong-Yun
    • Journal of KIISE:Databases
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    • v.34 no.1
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    • pp.84-97
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    • 2007
  • Selectivity estimation techniques in query optimization have been used in commercial databases and histograms are popularly used for the selectivity estimation. Recently, the techniques for spatio-temporal databases have been restricted to existing temporal and spatial databases. In addition, the selectivity estimation techniques focused on time-series data such as moving objects. It is also impossible to estimate selectivity for range queries with a time interval. Therefore, we construct two histograms, CMH (current multidimensional histogram) and PMH (past multidimensional histogram), to estimate the selectivity of multidimensional sequence data in spatio-temporal databases and propose effective selectivity estimation methods using the histograms. Furthermore, we solve a problem about the range query using our proposed histograms. We evaluated the effectiveness of histograms for range queries with a time interval through various experimental results.

Cell Selectivity of an Antimicrobial Peptide Melittin Diastereomer with D-amino Acid in the Leucine Zipper Sequence

  • Zhu, Wan Long;Nan, Yong Hai;Hahm, Kyung-Soo;Shin, Song-Yub
    • BMB Reports
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    • v.40 no.6
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    • pp.1090-1094
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    • 2007
  • Melittin (ME), a linear 26-residue non-cell-selective antimicrobial peptide, displays strong lytic activity against bacterial and human red blood cells. To design ME analogue with improved cell selectivity, we synthesized a melittin diastereomer (ME-D) with D-amino acid in the leucine zipper sequence (Leu-6, Lue-13 and Ile-20). Compared to ME, ME-D exhibited the same or 2-fold higher antibacterial activity but 8-fold less hemolytic activity. Circular dichroism analysis revealed that ME-D has much less $\alpha$-helical content in $\alpha$-helical content in the presence of zwitterionic EYPC/cholesterol (10 : 1, w/w) liposomes compared to negatively charged EYPE/EYPG (7 : 3, w/w) liposomes. The blue shift of the fluorescence emission maximum of ME-D in zwitterionic EYPC/cholesterol (10 : 1, w/w) liposomes was much smaller than in negatively charged EYPE/EYPG (7 : 3, w/w) liposomes. These results suggested that the improvement in therapeutic index/cell selectivity of ME-D is correlated with its less permeability to zwitterionic membranes.

Design and Synthesis of Metallopeptide Sensors: Tuning Selectivity with Ligand Variation

  • Kim, Joung-Min;Joshi, Bishnu Prasad;Lee, Keun-Hyeung
    • Bulletin of the Korean Chemical Society
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    • v.31 no.9
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    • pp.2537-2541
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    • 2010
  • We chose a fluorescent pentapeptide sensor (-CPGHE) containing a dansyl fluorophore as a model peptide and investigated whether the selectivity and sensitivity of the peptides for heavy and transition metal ions could be tuned by changing amino acid sequence. In this process, we developed a selective peptide sensor, Cp1-d (-HHPGE, $K_d\;=\;670\;nM$) for detection of $Zn^{2+}$ in 100% aqueous solution and a selective and sensitive peptide sensor, Cp1-e (-CCHPGE, $K_d\;=\;24\;nM$) for detection of $Cd^{2+}$ in 100% aqueous solution. Overall results indicate that the selectivity and sensitivity of the metallopeptide sensors to specific heavy and transition metal ions can be tuned by changing amino acid sequence.

Estimation of Substring Selectivity in Biological Sequence Database (생물학 서열 데이타베이스에서 부분 문자열의 선적도 추정)

  • 배진욱;이석호
    • Journal of KIISE:Databases
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    • v.30 no.2
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    • pp.168-175
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    • 2003
  • Until now, substring selectivities have been estimated by two steps. First step is to build up a count-suffix tree, which has statistical information about substrings, and second step is to estimate substring selectivity using it. However, it's actually impossible to build up a count-suffix tree from biological sequences because their lengths are too long. So, this paper proposes a novel data structure, count q-gram tree, consisting of fixed length substrings. The Count q-gram tree retains the exact counts of all substrings whose lengths are equal to or less than q and this tree is generated in 0(N) time and in site not subject to total length of all sequences, N. This paper also presents an estimation technique, k-MO. k-MO can choose overlapping length of splitted substrings from a query string, and this choice will affect accuracy of selectivity and query processing time. Experiments show k-MO can estimate very accurately.

Single-strand DNA Binding of Actinomycin D with a Chromophore 2-Amino to 2-Hydroxyl Substitution

  • Yoo, Hoon;Rill, Randolph L.
    • BMB Reports
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    • v.36 no.3
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    • pp.305-311
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    • 2003
  • A modified actinomycin D was prepared with a hydroxyl group that replaced the amino group at the chromophore 2-position, a substitution known to strongly reduce affinity for double-stranded DNA. Interactions of the modified drug on single-stranded DNAs of the defined sequence were investigated. Competition assays showed that 2-hydroxyactinomycin D has low affinity for two oligonucleotides that have high affinities ($K_a\;=\;5-10{\times}10^6\;M^{-1}$ oligomer) for 7-aminoactinomycin D and actinomycin D. Primer extension inhibition assays performed on several single-stranded DNA templates totaling around 1000 nt in length detected a single high affinity site for 2-hydroxyactinomycin D, while many high affinity binding sites of unmodified actinomycin D were found on the same templates. The sequence selectivity of 2-hydroxyactinomycin D binding is unusually high and approximates the selectivity of restriction endonucleases. Binding appears to require a complex structure, including residues well removed from the polymerase pause site.

Descriptor-Based Profile Analysis of Kinase Inhibitors to Predict Inhibitory Activity and to Grasp Kinase Selectivity

  • Park, Hyejin;Kim, Kyeung Kyu;Kim, ChangHoon;Shin, Jae-Min;No, Kyoung Tai
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2680-2684
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    • 2013
  • Protein kinases (PKs) are an important source of drug targets, especially in oncology. With 500 or more kinases in the human genome and only few kinase inhibitors approved, kinase inhibitor discovery is becoming more and more valuable. Because the discovery of kinase inhibitors with an increased selectivity is an important therapeutic concept, many researchers have been trying to address this issue with various methodologies. Although many attempts to predict the activity and selectivity of kinase inhibitors have been made, the issue of selectivity has not yet been resolved. Here, we studied kinase selectivity by generating predictive models and analyzing their descriptors by using kinase-profiling data. The 5-fold cross-validation accuracies for the 51 models were between 72.4% and 93.7% and the ROC values for all the 51 models were over 0.7. The phylogenetic tree based on the descriptor distance is quite different from that generated on the basis of sequence alignment.

Loop Selective Direction Measurement for Distance Protection

  • Steynberg, Gustav;Koch, Geyhard
    • Journal of Electrical Engineering and Technology
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    • v.1 no.4
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    • pp.423-426
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    • 2006
  • Distance relays achieve selective tripping by measurement of all short circuit fault conditions inside set reaches. The direction of the fault, forward or reverse is commonly determined with a dedicated measurement to ensure selectivity under all conditions. For the direction decision (measurement) a number of alternatives are available. This paper describes a loop selective direction measurement and illustrates by means of a typical fault why this is superior to a non loop selective direction measurement such as that based on negative sequence quantities.

A Directional Relay Algorithm Using Positive-Sequence Superimposed Quantity for Transmission Line Protection (정상 성분 변화량을 이용한 송전선로 보호용 방향 계전 알고리즘)

  • 이명수;유석구
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.52 no.4
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    • pp.226-233
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    • 2003
  • Directional elements are fundamental to protection scheme security and selectivity, performing such critical tasks as supervising distance elements and controlling overcurrent elements. But, conventional operating principles for directional detection based on negative or zero sequence quantify do not satisfy the requirements for improved sensitivity and fast operation under any fault conditions. In this paper, new algorithm for directional elements is proposed. The proposed algorithm use the positive-sequence superimposed voltages and currents in order to be used in all fault conditions. Also, because this algorithm uses a voltage compensation method. it can be well operated under strong source conditions.