Sökning: "unnatural amino acid"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden unnatural amino acid.

  1. 1. Exotic Ribosomal Enzymology

    Författare :Josefine Liljeruhm; Anthony C. Forster; Christophe Danelon; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; rRNA modification; Methyltransferase; RlmM; RlmJ; D-amino acid; Unnatural amino acid; Chromoprotein; Biology with specialization in Molecular Biology; Biologi med inriktning mot molekylärbiologi;

    Sammanfattning : This thesis clarifies intriguing enzymology of the ribosome, the multiRNA/multiprotein complex that catalyzes protein synthesis (translation). The large ribosomal RNAs (23S and 16S rRNAs in E. coli) are post-transcriptionally modified by many specific modification enzymes, yet the functions of the modifications remain enigmatic. LÄS MER

  3. 2. Rate and Accuracy of Bacterial Protein Synthesis with Natural and Unnatural Amino Acids

    Författare :Ka-Weng Ieong; Måns Ehrenberg; Simpson Joseph; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ribosome; protein synthesis; translation; efficiency-accuracy trade-off; kinetics; unnatural amino acids; Molecular Biology; Molekylärbiologi;

    Sammanfattning : This thesis addresses different questions regarding the rate, efficiency, and accuracy of peptide bond formation with natural as well as unnatural amino acids: Which step is rate-limiting during peptide bond formation? How does the accuracy vary with different transfer RNAs (tRNAs) and codons and how is it relevant to the living cells? Does proofreading selection of codon reading occur in a single- or multi-step manner as theoretically suggested? How does the E. coli translation system discriminate unnatural amino acids? Based on that, how to improve the incorporation efficiencies of unnatural amino acids?Based on the study on pH dependence of peptide bond formation, we show that the rate of the chemistry of peptidyl transfer to aminoacyl-tRNA (AA-tRNA) Gly-tRNAGly or Pro-tRNAPro limits the rate of peptide bond formation at physiological pH 7. LÄS MER

  4. 3. Structure-Function Relationships of Pi Class Glutathione Transferase Studied by Protein Engineering

    Författare :Usama M. Hegazy; Bengt Mannervik; Mikael Widersten; T. J. Mantle; Uppsala universitet; []
    Nyckelord :Biochemistry; Glutathione transferase; targeted chemical modification; lock-and-key motif; cooperativity; stucture-function relationship; protein engineering; unnatural amino acid; site-specific mutation; Biokemi;

    Sammanfattning : The glutathione transferases (GSTs) represent a superfamily of dimeric proteins involved in cellular detoxication by catalyzing the nucleophilic addition of the reduced glutathione (GSH) to the hydrophobic electrophiles. The present work focuses on the functional role of the conserved structures of GSTP1-1. LÄS MER

  5. 4. Synthesis of Non-Natural Aromatic Amino Acids Derivatives Solvent-free reactions-Versatile building blocks-Galectin inhibitors

    Författare :Erik Tullberg; Centrum för analys och syntes; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organisk kemi; Organic chemistry; Naturvetenskap; Natural science; Multivalent galectin inhibitors; Multifunctional molecules; Amino Acids; Solvent-free reactions;

    Sammanfattning : This thesis deals with three topics concerning the synthesis of non-natural also known as unnatural amino acid derivatives. In the first, solvent-free reaction conditions for the Heck reaction were developed that were superior to previous conditions because the reaction time could be reduced and the work-up procedure simplified. LÄS MER

  7. 5. Palladium(0)-Catalyzed Synthesis of Spirocycles and Supercritical Chemistry using a Resistively Heated Flow Reactor

    Författare :Ahmed Adeyemi; Mats Larhed; Luke R. Odell; Kenneth Wärnmark; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Continuous Flow; Resistive heating; Supercritical fluids; high-temperature synthesis; Mizoroki-Heck reaction; Spirooxindoles; Spiroethers; Spirobenzofuranes; Unnatural Amino Acids;

    Sammanfattning : This doctoral thesis focusses on an effective and selective approach to the synthesis of spirocycles using palladium(0)-catalyzed Mizoroki-Heck reactions. In addition, selective and efficient chemistry was highlighted by the design and evaluation of a novel resistively heated system for continuous flow (CF) synthesis for high-temperature and high-pressure applications. LÄS MER