• Title/Summary/Keyword: computational biology

Search Result 204, Processing Time 0.025 seconds

A DNA Sequence Alignment Algorithm Using Quality Information and a Fuzzy Inference Method (품질 정보와 퍼지 추론 기법을 이용한 DNA 염기 서열 배치 알고리즘)

  • Kim, Kwang-Baek
    • Journal of Intelligence and Information Systems
    • /
    • v.13 no.2
    • /
    • pp.55-68
    • /
    • 2007
  • DNA sequence alignment algorithms in computational molecular biology have been improved by diverse methods. In this paper, we proposed a DNA sequence alignment algorithm utilizing quality information and a fuzzy inference method utilizing characteristics of DNA sequence fragments and a fuzzy logic system in order to improve conventional DNA sequence alignment methods using DNA sequence quality information. In conventional algorithms, DNA sequence alignment scores were calculated by the global sequence alignment algorithm proposed by Needleman-Wunsch applying quality information of each DNA fragment. However, there may be errors in the process for calculating DNA sequence alignment scores in case of low quality of DNA fragment tips, because overall DNA sequence quality information are used. In the proposed method, exact DNA sequence alignment can be achieved in spite of low quality of DNA fragment tips by improvement of conventional algorithms using quality information. And also, mapping score parameters used to calculate DNA sequence alignment scores, are dynamically adjusted by the fuzzy logic system utilizing lengths of DNA fragments and frequencies of low quality DNA bases in the fragments. From the experiments by applying real genome data of NCBI (National Center for Biotechnology Information), we could see that the proposed method was more efficient than conventional algorithms using quality information in DNA sequence alignment.

  • PDF

Hypernetwork Classifiers for Microarray-Based miRNA Module Analysis (마이크로어레이 기반 miRNA 모듈 분석을 위한 하이퍼망 분류 기법)

  • Kim, Sun;Kim, Soo-Jin;Zhang, Byoung-Tak
    • Journal of KIISE:Software and Applications
    • /
    • v.35 no.6
    • /
    • pp.347-356
    • /
    • 2008
  • High-throughput microarray is one of the most popular tools in molecular biology, and various computational methods have been developed for the microarray data analysis. While the computational methods easily extract significant features, it suffers from inferring modules of multiple co-regulated genes. Hypernetworhs are motivated by biological networks, which handle all elements based on their combinatorial processes. Hence, the hypernetworks can naturally analyze the biological effects of gene combinations. In this paper, we introduce a hypernetwork classifier for microRNA (miRNA) profile analysis based on microarray data. The hypernetwork classifier uses miRNA pairs as elements, and an evolutionary learning is performed to model the microarray profiles. miTNA modules are easily extracted from the hypernetworks, and users can directly evaluate if the miRNA modules are significant. For experimental results, the hypernetwork classifier showed 91.46% accuracy for miRNA expression profiles on multiple human canters, which outperformed other machine learning methods. The hypernetwork-based analysis showed that our approach could find biologically significant miRNA modules.

Computational Prediction of Alzheimer's and Parkinson's Disease MicroRNAs in Domestic Animals

  • Wang, Hai Yang;Lin, Zi Li;Yu, Xian Feng;Bao, Yuan;Cui, Xiang-Shun;Kim, Nam-Hyung
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.29 no.6
    • /
    • pp.782-792
    • /
    • 2016
  • As the most common neurodegenerative diseases, Alzheimer's disease (AD) and Parkinson's disease (PD) are two of the main health concerns for the elderly population. Recently, microRNAs (miRNAs) have been used as biomarkers of infectious, genetic, and metabolic diseases in humans but they have not been well studied in domestic animals. Here we describe a computational biology study in which human AD- and PD-associated miRNAs (ADM and PDM) were utilized to predict orthologous miRNAs in the following domestic animal species: dog, cow, pig, horse, and chicken. In this study, a total of 121 and 70 published human ADM and PDM were identified, respectively. Thirty-seven miRNAs were co-regulated in AD and PD. We identified a total of 105 unrepeated human ADM and PDM that had at least one 100% identical animal homolog, among which 81 and 54 showed 100% sequence identity with 241 and 161 domestic animal miRNAs, respectively. Over 20% of the total mature horse miRNAs (92) showed perfect matches to AD/PD-associated miRNAs. Pigs, dogs, and cows have similar numbers of AD/PD-associated miRNAs (63, 62, and 59). Chickens had the least number of perfect matches (34). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses suggested that humans and dogs are relatively similar in the functional pathways of the five selected highly conserved miRNAs. Taken together, our study provides the first evidence for better understanding the miRNA-AD/PD associations in domestic animals, and provides guidance to generate domestic animal models of AD/PD to replace the current rodent models.

Combining Support Vector Machine Recursive Feature Elimination and Intensity-dependent Normalization for Gene Selection in RNAseq (RNAseq 빅데이터에서 유전자 선택을 위한 밀집도-의존 정규화 기반의 서포트-벡터 머신 병합법)

  • Kim, Chayoung
    • Journal of Internet Computing and Services
    • /
    • v.18 no.5
    • /
    • pp.47-53
    • /
    • 2017
  • In past few years, high-throughput sequencing, big-data generation, cloud computing, and computational biology are revolutionary. RNA sequencing is emerging as an attractive alternative to DNA microarrays. And the methods for constructing Gene Regulatory Network (GRN) from RNA-Seq are extremely lacking and urgently required. Because GRN has obtained substantial observation from genomics and bioinformatics, an elementary requirement of the GRN has been to maximize distinguishable genes. Despite of RNA sequencing techniques to generate a big amount of data, there are few computational methods to exploit the huge amount of the big data. Therefore, we have suggested a novel gene selection algorithm combining Support Vector Machines and Intensity-dependent normalization, which uses log differential expression ratio in RNAseq. It is an extended variation of support vector machine recursive feature elimination (SVM-RFE) algorithm. This algorithm accomplishes minimum relevancy with subsets of Big-Data, such as NCBI-GEO. The proposed algorithm was compared to the existing one which uses gene expression profiling DNA microarrays. It finds that the proposed algorithm have provided as convenient and quick method than previous because it uses all functions in R package and have more improvement with regard to the classification accuracy based on gene ontology and time consuming in terms of Big-Data. The comparison was performed based on the number of genes selected in RNAseq Big-Data.

Biochemical Characterization of Exoribonuclease Encoded by SARS Coronavirus

  • Chen, Ping;Jiang, Miao;Hu, Tao;Liu, Qingzhen;Chen, Xiaojiang S.;Guo, Deyin
    • BMB Reports
    • /
    • v.40 no.5
    • /
    • pp.649-655
    • /
    • 2007
  • The nsp14 protein is an exoribonuclease that is encoded by severe acute respiratory syndrome coronavirus (SARS-CoV). We have cloned and expressed the nsp14 protein in Escherichia coli, and characterized the nature and the role(s) of the metal ions in the reaction chemistry. The purified recombinant nsp14 protein digested a 5'-labeled RNA molecule, but failed to digest the RNA substrate that is modified with fluorescein group at the 3'-hydroxyl group, suggesting a 3'-to-5' exoribonuclease activity. The exoribonuclease activity requires $Mg^{2+}$ as a cofactor. Isothermal titration calorimetry (ITC) analysis indicated a two-metal binding mode for divalent cations by nsp14. Endogenous tryptophan fluorescence and circular dichroism (CD) spectra measurements showed that there was a structural change of nsp14 when binding with metal ions. We propose that the conformational change induced by metal ions may be a prerequisite for catalytic activity by correctly positioning the side chains of the residues located in the active site of the enzyme.

p-Coumaric Acid Potently Down-regulates Zebrafish Embryo Pigmentation: Comparison of in vivo Assay and Computational Molecular Modeling with Phenylthiourea

  • Kim, Dong-Chan;Kim, Seonlin;Hwang, Kyu-Seok;Kim, Cheol-Hee
    • Biomedical Science Letters
    • /
    • v.23 no.1
    • /
    • pp.8-16
    • /
    • 2017
  • p-Coumaric acid is an organic compound that is a hydroxyl derivative of cinnamic acid. Due to its multiple biological activities p-coumaric acid has been widely studied in biochemical and cellular systems and is also considered as a useful therapeutic candidate for various neuronal diseases. However, the efficacy of p-coumaric acid on zebrafish developmental regulation has not been fully explored. In this study, therefore, we first investigated the action mechanism of the p-coumaric acid on the zebrafish development in a whole-organism model. p-Coumaric acid treated group significantly inhibited the pigmentation of the developing zebrafish embryos compared with control embryos without any severe side effects. In addition, p-coumaric acid down-regulated more effectively in a lower concentration than the well-known zebrafish's melanogenic inhibitor, phenylthiourea. We also compared the molecular docking property of p-coumaric acid with phenylthiourea on the tyrosinase's kojic acid binding site, which is the key enzyme of zebrafish embryo pigmentation. Interestingly, p-coumaric acid interacted with higher numbers of the amino acid residues and exhibited a tight binding affinity to the enzyme than phenylthiourea. Taken all together, these results strongly suggest that p-coumaric acid inhibits the activity of tyrosinase, consequently down-regulating zebrafish embryo pigmentation, and might play an important role in the reduction of dermal pigmentation. Thus, p-coumaric acid can be an effective and non-toxic ingredient for anti-melanogenesis functional materials.

Discovery of Cyclin-dependent Kinase Inhibitor, CR229, Using Structure-based Drug Screening

  • Kim, Min-Kyoung;Min, Jae-Ki;Choi, Bu-Young;Lim, Hae-Young;Cho, Youl-Hee;Lee, Chul-Hoon
    • Journal of Microbiology and Biotechnology
    • /
    • v.17 no.10
    • /
    • pp.1712-1716
    • /
    • 2007
  • To generate new scaffold candidates as highly selective and potent cyelin-dependent kinase (CDK) inhibitors, structure-based drug screening was performed utilizing 3D pharmacophore conformations of known potent inhibitors. As a result, CR229 (6-bromo-2,3,4,9-tetrahydro-carbolin-1-one) was generated as the hit-compound. A computational docking study using the X-ray crystallographic structure of CDK2 in complex with CR229 was evaluated. This predicted binding mode study of CR229 with CDK2 demonstrated that CR229 interacted effectively with the Leu83 and Glu81 residues in the ATP-binding pocket of CDK2 for the possible hydrogen bond formation. Furthermore, biochemical studies on inhibitory effects of CR229 on various kinases in the human cervical cancer HeLa cells demonstrated that CR229 was a potent inhibitor of CDK2 ($IC_{50}:\;3\;{\mu}M$), CDKI ($IC_{50}:\;4.9\;{\mu}M$), and CDK4 ($IC_{50}:\;3\;{\mu}M$), yet had much less inhibitory effect ($IC_{50}:>20\;{\mu}M$) on other kinases, such as casein kinase 2-${\alpha}1$ (CK2-${\alpha}1$), protein kinase A (PKA), and protein kinase C (PKC). Accordingly, these data demonstrate that CR229 is a potent CDK inhibitor with anticancer efficacy.

Validation and Application of a Real-time PCR Protocol for the Specific Detection and Quantification of Clavibacter michiganensis subsp. sepedonicus in Potato

  • Cho, Min Seok;Park, Duck Hwan;Namgung, Min;Ahn, Tae-Young;Park, Dong Suk
    • The Plant Pathology Journal
    • /
    • v.31 no.2
    • /
    • pp.123-131
    • /
    • 2015
  • Clavibacter michiganensis subsp. sepedonicus (Cms) multiplies very rapidly, passing through the vascular strands and into the stems and petioles of a diseased potato. Therefore, the rapid and specific detection of this pathogen is highly important for the effective control of the pathogen. Although several PCR assays have been developed for detection, they cannot afford specific detection of Cms. Therefore, in this study, a computational genome analysis was performed to compare the sequenced genomes of the C. michiganensis subspecies and to identify an appropriate gene for the development of a subspecies-specific PCR primer set (Cms89F/R). The specificity of the primer set based on the putative phage-related protein was evaluated using genomic DNA from seven isolates of Cms and 27 other reference strains. The Cms89F/R primer set was more specific and sensitive than the existing assays in detecting Cms in in vitro using Cms cells and its genomic DNA. This assay was also able to detect at least $1.47{\times}10^2copies/{\mu}l$ of cloned-amplified target DNA, 5 fg of DNA using genomic DNA or $10^{-6}$ dilution point of 0.12 at $OD_{600}$ units of cells per reaction using a calibrated cell suspension.

Differential Expression Profiling of Salivary Exosomal microRNAs in a Single Case of Periodontitis - A Pilot Study

  • Park, Sung Nam;Son, Young Woo;Choi, Eun Joo;You, Hyung-Keun;Kim, Min Seuk
    • International Journal of Oral Biology
    • /
    • v.43 no.4
    • /
    • pp.223-230
    • /
    • 2018
  • Exosomes are Nano-sized lipid vesicles secreted from mammalian cells containing diverse cellular materials such as proteins, lipids, and nucleotides. Multiple lines of evidence indicate that in saliva, exosomes and their contents such as microRNAs (miRNAs) mediate numerous cellular responses upon delivery to recipient cells. The objective of this study was to characterize the different expression profile of exosomal miRNAs in saliva samples, periodically isolated from a single periodontitis patient. Unstimulated saliva was collected from a single patient over time periods for managing periodontitis. MicroRNAs extracted from each phase were investigated for the expression of exosomal miRNAs. Salivary exosomal miRNAs were analyzed using Affymetrix miRNA arrays and prediction of target genes and pathways for its different expression performed using DIANA-mirPath, a web-based, computational tool. Following the delivery of miRNA mimics (hsa-miR-4487, -4532, and -7108-5p) into human gingival fibroblasts, the expression of pro-inflammatory cytokines and activation of the MAPK pathway were evaluated through RT-PCR and western blotting. In each phase, 13 and 43 miRNAs were found to be differently expressed $({\mid}FC{\mid}{\geq}2)$. Among these, hsa-miR-4487 $({\mid}FC{\mid}=9.292005)$ and has-miR-4532 $({\mid}FC{\mid}=18.322697)$ were highly up-regulated in the clinically severe phase, whereas hsa-miR-7108-5p $({\mid}FC{\mid}=12.20601)$ was strongly up-regulated in the clinically mild phase. In addition, the overexpression of miRNA mimics in human gingival fibroblasts resulted in a significant induction of IL-6 mRNA expression and p38 phosphorylation. The findings of this study established alterations in salivary exosomal miRNAs which are dependent on the severity of periodontitis and may act as potential candidates for the treatment of oral inflammatory diseases.

Ginsenoside Rg3, a promising agent for NSCLC patients in the pandemic: a large-scale data mining and systemic biological analysis

  • Zhenjie Zhuang;Qianying Chen;Xiaoying Zhong;Huiqi Chen;Runjia Yu;Ying Tang
    • Journal of Ginseng Research
    • /
    • v.47 no.2
    • /
    • pp.291-301
    • /
    • 2023
  • Introduction: Non-small cell lung cancer (NSCLC) patients are particularly vulnerable to the Coronavirus Disease-2019 (COVID-19). Currently, no anti-NSCLC/COVID-19 treatment options are available. As ginsenoside Rg3 is beneficial to NSCLC patients and has been identified as an entry inhibitor of the virus, this study aims to explore underlying pharmacological mechanisms of ginsenoside Rg3 for the treatment of NSCLC patients with COVID-19. Methods: Based on a large-scale data mining and systemic biological analysis, this study investigated target genes, biological processes, pharmacological mechanisms, and underlying immune implications of ginsenoside Rg3 for NSCLC patients with COVID-19. Results: An important gene set containing 26 target genes was built. Target genes with significant prognostic value were identified, including baculoviral IAP repeat containing 5 (BIRC5), carbonic anhydrase 9 (CA9), endothelin receptor type B (EDNRB), glucagon receptor (GCGR), interleukin 2 (IL2), peptidyl arginine deiminase 4 (PADI4), and solute carrier organic anion transporter family member 1B1 (SLCO1B1). The expression of target genes was significantly correlated with the infiltration level of macrophages, eosinophils, natural killer cells, and T lymphocytes. Ginsenoside Rg3 may benefit NSCLC patients with COVID-19 by regulating signaling pathways primarily involved in anti-inflammation, immunomodulation, cell cycle, cell fate, carcinogenesis, and hemodynamics. Conclusions: This study provided a comprehensive strategy for drug discovery in NSCLC and COVID-19 based on systemic biology approaches. Ginsenoside Rg3 may be a prospective drug for NSCLC patients with COVID-19. Future studies are needed to determine the value of ginsenoside Rg3 for NSCLC patients with COVID-19.