Chem-Bio Informatics Journal
Online ISSN : 1347-0442
Print ISSN : 1347-6297
ISSN-L : 1347-0442
Volume 4, Issue 4
Displaying 1-4 of 4 articles from this issue
Original
  • Keiji Kakumoto, Shota Yamanaka, Chikuma Hamada, Isao Yoshimura
    2004 Volume 4 Issue 4 Pages 121-132
    Published: 2004
    Released on J-STAGE: January 10, 2005
    JOURNAL FREE ACCESS
    Statistical analysis was conducted to study the efficiency of methods for active compound selection by comparing the method of screening a test compound set by an in silico method DOCK using a target protein (receptor) of a known structure versus the method of screening by the standard in vitro assays and also to determine how best to utilize the DOCK output variables. In this study we used DOCK output data on 327 compounds and the in vitro assay data on synthetic product resulting from an enzymatic reaction of a given substrate, and those compounds giving greater than 50% inhibition activity in an in vitro assay were considered to be active compounds. The representative variables were selected from a group of variables with mutually high correlation in the 108 DOCK output variables and subjected to liberal variable selection or conservative variable selection by the stepwise selection-elimination method of the logistic regression model, yielding 16 and 3 variables, respectively. These variables were then used for screening by the logistic regression method, and the performance was evaluated by the jackknife method (a performance evaluation method in which a measured value predicted from the n-1 observations removing the own predicted observation). The results indicated that elimination of about 80% of test compounds by DOCK in silico screening gave 80% sensitivity and 15% false positive rate. We demonstrate the usefullness of in silico screening using a prediction model by logistic regression.
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  • Satoshi Mizuta, Hikaru Munakata, Abulimiti Aimaiti, Kenji Oosawa, Tosh ...
    2004 Volume 4 Issue 4 Pages 133-141
    Published: 2004
    Released on J-STAGE: January 10, 2005
    JOURNAL FREE ACCESS
    By using the color-coding (CC) method, which is based on visual inspection by eyes, tandem repeats (TRs) were searched in the Yersinia pestis, Deinococcus radiodurans and Haemophilus influenzae genomes by three independent inspectors, and the detected TRs were compared to investigate the individual variations among inspectors in detecting TRs. We also compared the CC method with Tandem Repeats Finder (TRF) that is one of the algorithmic methods for searching TRs, in the detection ability of TRs, demonstrating that the CC method can get much larger number of TRs than TRF, even long TRs with much lower sequence identity.
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  • Masahiro Gomi, Masashi Sonoyama, Shigeki Mitaku
    2004 Volume 4 Issue 4 Pages 142-147
    Published: 2004
    Released on J-STAGE: January 10, 2005
    JOURNAL FREE ACCESS
    We describe a novel method for predicting a signal peptide of which three-domain (tripartite) structure is recognized by three modules of the software system. The first module numerates hydrophobic segment in N-terminal 100 residues, the second predicts signal sequences including both signal peptides and signal anchors, and the third discriminates signal peptides. Two novel indexes, SS- and SP-indexes, were developed for the discrimination of signal sequences and signal peptides, respectively, by calculating the relative propensities of amino acids at the carboxyl-terminal end of the hydrophobic region. The number of adjustable parameters in the whole system was only five. When three groups of data (917 signal peptides, 103 signal anchors and 544 non-signal sequences) were analyzed, signal peptides of eukaryotes could be discriminated with the Matthews correlation coefficient of 0.89. The signal peptide predictor SOSUIsignal is available at the web site: http://bp.nuap.nagoya-u.ac.jp/sosui/sosuisignal/sosuisignal_submit.html. This system has the advantage of very fast calculation.
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