TAILIEUCHUNG - Báo cáo khoa học: Role of conformational flexibility for enzymatic activity in NADH oxidase from Thermus thermophilus

NADHoxidase fromThermus thermophilusis a homodimer with anunknownphysiological function. As is typical for an enzyme isolated froma thermophile,the catalytic rate,kcat,is low at low temperatures and increases with temperature, achieving an optimum at the physiological temperature of the organism,. at 70 CforT. temperatures,thekcatof several enzymes from thermophilic and mesophilic organisms can be increased by chaotropic agents. | Eur. J. Biochem. 270 4887-4897 2003 FEBS 2003 doi Role of conformational flexibility for enzymatic activity in NADH oxidase from Thermus thermophilus Gabriel Zoldak1 Robert Sut ak1 2 Marian Antalik1 3 Mathias Sprinzl4 and Erik Sedlak1 1 Department of Biochemistry Faculty of Sciences P. J. Safarik University Kosice Slovakia department of Parasitology Charles University Prague Czech Republic 3Department of Biophysics Institute of Experimental Physics Slovak Academy of Sciences Kosice Slovakia 4Laboratorium fur Biochemie Universitat Bayreuth Germany NADH oxidase from Thermus thermophilus is a homodimer with an unknown physiological function. As is typical for an enzyme isolated from a thermophile Ihe catalytic rate. kcat is low at low temperatures and increases with temperature achieving an optimum at the physiological temperature of the organism . at w 70 C for T. thermophilus. At low temperatures hie kcat of several enzymes from thermophilic and mesophilic organisms can be increased by chaotropic agents. The catalytic rate of NADH oxidase increases in the presence of urea. At concentrations of M urea it reaches 250 of the activity in the absence of urea at 20 C. At higher urea concentrations the enzyme activity is inhibited. The urea-dependent activity changes correlate with changes in the fluorescence intensity of Trp47 which is located in the active site of the enzyme. Both fluorescence and circular dichroism measurements indicate that the acti vation by chaotropic agents involves local environmental changes accompanied by increased dynamics in the active site of the enzyme. This is not related to the global structure of NADH oxidase. The presence of an aromatic amino acid interacting with the flavin cofactor is common to numerous flavin-dependent oxidases. A comparison of the crystal structure with the activation thermodynamic parameters DH and TAS ohaiined I oom hie temperature dependence of kcat suggests that Trp47 .

• Báo cáo khoa học
• scientific reports
• Report medicine
• traditional medicine
• medical knowledge
• medical research
• analysis of cytoplasmic
• collection of scientific reports
• industry reports philosophy of history reports
• reports in literature
• a scientific b shirt
• presentation of scientific reports
• reports on literature
• philosophy statement
• documents
• studies English language and English language communication and English language commercial
• progress reports at scientific collections
• agronomic reports
• reports in physics
• biology reports
• thematic biological
• induced geometry
• mathematical topics
• quantum mechanics
• physics
• reporting mathematics
• physics reports
• livestock reports
• physical reports
• research physicist
• specializing in physics
• mathematical statements
• mathematical equations
• English pronunciation
• presentation report
• agricultural reports
• technical crops
• bio technology
• English reports
• scientific research
• presentation reports
• mathematical knowledge
• reports of mathematics
• represented
• Wilf on packing distinct
• Tur´n density
• mathematical works
• patterns in a permutation
• statements and documents scientific reports
• reports agronomy
• biotechnology
• plants Vietnam
• specialized biological
• microbiological methods
• presenting the report
• anti bacterial properties of shrimp
• energy exchange
• engineering chicken
• Path counting
• random matrix theory
• Even circuits
• prescribed clockwise parity
• Correspondence between
• algorithmic characterizations
• Finding Induced Acyclic
• Random Digraphs
• Nonexistence results
• Hadamard like matrices
• Voltage Graphs
• Group Presentations
• Cages mathematical knowledge
• Dominance Order
• Graphical Partitions
• On the functions
• values in [α(G
• Box With Translates
• Two Given Rectangular Brick
• On the q analogue
• the sum of cubes