• Title/Summary/Keyword: Molecular Recognition

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Aptamers as Functional Nucleic Acids: in vitro Selection and Biotechnological Applications

  • You, Kyung-Man;Lee, Sang-Hyun;Aesul Im;Lee, Sun-Bok
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.2
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    • pp.64-75
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    • 2003
  • Aptamers are functional nucleic acids that can specially bind to proteins, peptides, amino acids. nucleotides, drugs, vitamins and other organic and inorganic compounds. The aptamers are identified from random DNA or RNA libraries by a SELEX (systematic evolution of ligands by exponential amplification) process. As aptamers have the advantage, and potential ability to be released from the limitations of antibodies, they are attractive to a wide range of therapeutic and diagnostic applications. Aptamers, with a high-affinity and specificity, could fulfil molecular the recognition needs of various fields in biotechnology. In this work, we reviewed some aptamer Selection techniques, properties, medical applications of their molecules and their biotechnological applications, such as ELONA (enzyme linked oligonucleotide assay), flow cytometry, biosensors, electrophoresis, chromatography and microarrays.

RNA-Protein Interactions and Protein-Protein Interactions during Regulation of Eukaryotic Gene Expression

  • Varani, Luca;Ramos, Andres;Cole, Pual T.;Neuhaus, David;Varani, Gabriele
    • Journal of the Korean Magnetic Resonance Society
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    • v.2 no.2
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    • pp.152-157
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    • 1998
  • The diversity of RNA functions ranges from storage and propagation of genetic information to enzymatic activity during RNA processing and protein synthesis. This diversity of functions requires an equally diverse arrays of structures, and, very often, the formation of functional RNA-protein complexes. Recognition of specific RNA signals by RNA-binding proteins is central to all aspects of post-transcriptional regulation of gene expression. We will describe how NMR is being used to understand at the atomic level how these important biological processes occur.

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Transfer RNA Acceptor Stem Determinants for Specific Aminoacylation by Class II Aminoacyl-tRNA Synthetases

  • Musier, Karin
    • BMB Reports
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    • v.31 no.6
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    • pp.525-535
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    • 1998
  • A critical step in the faithful translation of genetic information is specific tRNA recognition by aminoacyl-tRNA synthetases. These enzymes catalyze the covalent attachment of particular amino acids to the terminal adenosine of cognate tRNA substrates. In general, there is one synthetase for each of the twenty amino acids and each enzyme must discriminate against all of the cellular tRNAs that are specific for the nineteen noncognate amino acids. Primary sequence information combined with structural data have resulted in the division of the twenty synthetases into two classes. In recent years, several high-resolution co-crystal structures along with biochemical data have led to an increased understanding of tRNA recognition by synthetases of both classes. The anticodon sequence and the amino acid acceptor stem are the most common locations for critical recognition elements. This review will focus on acceptor stem discrimination by class II synthetases. In particular, the results of in vitro aminoacylation assays and site-directed and atomic group mutagenesis studies will be discussed. These studies have revealed that even subtle atomic determinants can provide signals for specific tRNA aminoacylation.

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Molecular Mechanisms Involved in Bacterial Speck Disease Resistance of Tomato

  • Kim, Young-Jin;Gregory B. Martin
    • The Plant Pathology Journal
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    • v.20 no.1
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    • pp.7-12
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    • 2004
  • An important recent advance in the field of plant-microbe interactions has been the cloning of genes that confer resistance to specific viruses, bacteria, fungi or insects. Disease resistance (R) genes encode proteins with predicted structural motifs consistent with them having roles in signal recognition and transduction. Plant disease resistance is the result of an innate host defense mechanism, which relies on the ability of plant to recognize pathogen invasion and efficiently mount defense responses. In tomato, resistance to the pathogen Pseudomonas syringae pv. tomato is mediated by the specific recognition between the tomato serine/threonine kinase Pto and bacterial protein AvrPto or AvrPtoB. This recognition event initiates signaling events that lead to defense responses including an oxidative burst, the hypersensitive response (HR), and expression of pathogenesis- related genes.

Analysis of Polymer Characteristics Using Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry (말디토프 질량분석을 이용한 고분자의 특성분석)

  • Kang, Min-Jung;Seong, Yunseo;Kim, Moon-Ju;Kim, Myung Soo;Pyun, Jae-Chul
    • Applied Chemistry for Engineering
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    • v.28 no.3
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    • pp.263-271
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    • 2017
  • The application of mass spectrometry to polymer science has rapidly increased since the development of MALDI-TOF MS. This review summarizes current polymer analysis methods using MALDI-TOF MS, which has been extensively applied to analyze the average molecular weight of biopolymers and synthetic polymers. Polymer sequences have also been analyzed to reveal the structures and composition of monomers. In addition, the analysis of unknown end-groups and the determination of polymer concentrations are very important applications. Hyphenated techniques using MALDI-tandem MS have been used for the analysis of fragmentation patterns and end-groups, and also the combination of SEC and MALDI-TOF MS techniques is recommended for the analysis of complex polymers. Moreover, MALDI-TOF MS has been utilized for the observation of polymer degradation. Ion mobility MS, TOF-SIMS, and MALDI-TOF-imaging are also emerging technologies for polymer characterization because of their ability to automatically fractionate and localize polymer samples. The determination of polymer characteristics and their relation to the material properties is one of the most important demands for polymer scientists; the development of software and instrument for higher molecular mass range (> 100 kD) will increase the applications of MALDI-TOF MS for polymer scientists.