Sökning: "active site titration"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden active site titration.

1. 1. Lipase chemoselectivity - kinetics and applications

   Författare :Cecilia Hedfors; Karl Hult; Mats Martinelle; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Candida antarctica lipase B; Rhizomucor miehei lipase; active site titration; kinetics; chemoselectivity; thiol; alcohol; thiol-functionalized polyesters; Biochemistry; Biokemi;

   Sammanfattning :   A chemoselective catalyst is preferred in a chemical reaction where protecting groups otherwise are needed. The two lipases Candida antarctica lipase B and Rhizomucor miehei lipase showed large chemoselectivity ratios, defined as (kcat/KM)OH / (kcat/KM)SH, in a transacylation reaction with ethyl octanoate as acyl donor and hexanol or hexanethiol as acyl acceptor (paper I). LÄS MER

3. 2. Thiopurine S-methyltransferase - characterization of variants and ligand binding

   Författare :Annica Blissing; Lars-Göran Mårtensson; Tomas Nyman; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Thiopurine S-methyltransferase TPMT ; protein stability; enzyme kinetics; ligand binding; isothermal titration calorimetry ITC ; 8-anilinonaphthalene-1-sulfonic acid ANS ;

   Sammanfattning : Thiopurine S-methyltransferase (TPMT) belongs to the Class I S-adenosylmethionine-dependent methyltransferase (SAM-MT) super family of structurally related proteins. Common to the members of this large protein family is the catalysis of methylation reactions using S-adenosylmethionine (SAM) as a methyl group donor, although SAM-MTs act on a wide range of different substrates and carry out numerous biologically important functions. LÄS MER

4. 3. Lipases as Biocatalysts in Organic Media. Influence of Enzyme Preparation and Reaction Conditions on Activity and Selectivity

   Författare :Mattias Persson; Avdelningen för klinisk kemi och farmakologi; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Biochemical technology; Bioteknik; Biotechnology; water activity; temperature; enantioselectivity; immobilisation; organic solvents; lyophilisation; Lipases; Accurel EP-100; Biokemisk teknik; Proteins; enzymology; Proteiner; enzymologi;

   Sammanfattning : The discovery that enzymes can function in organic solvents has broadened the scope of biocatalysis, making enzymes highly useful tools for organic chemists. The widespread use of enzymes as catalysts in organic solvents has, however, been limited by the low activity obtained for enzymes in organic solvents compared to aqueous solutions. LÄS MER

5. 4. Structural and functional studies on glutaredoxins and members of the thioredoxin superfamily

   Författare :Johan Sagemark; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :;

   Sammanfattning : The active site of E.coli glutaredoxin 3 was investigated using a combination of experimental and theoretical techniques. Starting from different conformations, molecular dynamics simulations converged to an active site conformation where the Cys11 thiolate was hydrogen bonded to surrounding amide protons and to the thiol proton of Cys14. LÄS MER

7. 5. Tissue Factor in Complex : Studies of interactions between blood coagulation proteins

   Författare :Karin Carlsson; Magdalena Svensson; Susanne Wisén; Linköpings universitet; []
   Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

   Sammanfattning : Many biological processes rely on specific protein-protein interactions, for example immune responses, cell signaling, transcription, and blood coagulation. Blood coagulation is initiated when a vessel wall is damaged, exposing tissue factor (TF) to the circulating factor VII/factor VIIa (FVII/FVIIa) which results in the formation of the TF:FVIIa complex and thereby the initiation of blood coagulation. LÄS MER