The Experts below are selected from a list of 10164 Experts worldwide ranked by ideXlab platform
Angela M. Gronenborn - One of the best experts on this subject based on the ideXlab platform.
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Fast folding of a prototypic polypeptide: the immunoglobulin binding domain of streptococcal protein G.
Protein Science, 1994Co-Authors: John Kuszewski, G. Marius Clore, Angela M. GronenbornAbstract:The folding of the small (56 residues) highly stable B1 immunoglobulin binding domain (GB1) of streptococcal protein G has been investigated by quenched-flow Deuterium-Hydrogen Exchange. This system represents a paradigm for the study of protein folding because it exhibits no complicating features superimposed upon the intrinsic properties of the polypeptide chain. Collapse to a semicompact state exhibiting partial order, reflected in protection factors for ND-NH Exchange up to 10-fold higher than that expected for a random coil, occurs within the dead time (< or = 1 ms) of the quenched flow apparatus. This is followed by the formation of the fully native state, as monitored by the fractional proton occupancy of 26 backbone amide groups spread throughout the protein, in a single rapid concerted step with a half-life of 5.2 ms at 5 degrees C.
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Kinetics of folding of the all-beta sheet protein interleukin-1 beta
Science, 1993Co-Authors: P Varley, Angela M. Gronenborn, H Christensen, Paul T. Wingfield, Roger H. Pain, G. Marius CloreAbstract:The folding of the all-beta sheet protein, interleukin-1 beta, was studied with nuclear magnetic resonance (NMR) spectroscopy, circular dichroism, and fluorescence. Ninety percent of the beta structure present in the native protein, as monitored by far-ultraviolet circular dichroism, was attained within 25 milliseconds, correlating with the first kinetic phase determined by tryptophan and 1-anilinonaphthalene-8-sulfonate fluorescence. In contrast, formation of stable native secondary structure, as measured by quenched-flow Deuterium-Hydrogen Exchange experiments, began after only 1 second. Results from the NMR experiments indicated the formation of at least two intermediates with half-lives of 0.7 to 1.5 and 15 to 25 seconds. The final stabilization of the secondary structure, however, occurs on a time scale much greater than 25 seconds. These results differ from previous results on mixed alpha helix-beta sheet proteins in which both the alpha helices and beta sheets were stabilized very rapidly (less than 10 to 20 milliseconds).
Kathrin U Jansen - One of the best experts on this subject based on the ideXlab platform.
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three dimensional structure and biophysical characterization of staphylococcus aureus cell surface antigen manganese transporter mntc
Journal of Molecular Biology, 2013Co-Authors: Alexey V Gribenko, Lidia Mosyak, Sharmistha Ghosh, Kevin Parris, Kristine Svenson, Justin Keith Moran, Ling Chu, Tong Liu, Virgil L Woods, Kathrin U JansenAbstract:Abstract MntC is a metal-binding protein component of the Mn 2 + -specific mntABC transporter from the pathogen Staphylococcus aureus . The protein is expressed during the early stages of infection and was proven to be effective at reducing both S. aureus and Staphylococcus epidermidis infections in a murine animal model when used as a vaccine antigen. MntC is currently being tested in human clinical trials as a component of a multiantigen vaccine for the prevention of S. aureus infections. To better understand the biological function of MntC, we are providing structural and biophysical characterization of the protein in this work. The three-dimensional structure of the protein was solved by X-ray crystallography at 2.2 A resolution and suggests two potential metal binding modes, which may lead to reversible as well as irreversible metal binding. Precise Mn 2 + -binding affinity of the protein was determined from the isothermal titration calorimetry experiments using a competition approach. Differential scanning calorimetry experiments confirmed that divalent metals can indeed bind to MntC reversibly as well as irreversibly. Finally, Mn 2 + -induced structural and dynamics changes have been characterized using spectroscopic methods and Deuterium–Hydrogen Exchange mass spectroscopy. Results of the experiments show that these changes are minimal and are largely restricted to the structural elements involved in metal coordination. Therefore, it is unlikely that antibody binding to this antigen will be affected by the occupancy of the metal-binding site by Mn 2 + .
Victor M Fernandez - One of the best experts on this subject based on the ideXlab platform.
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kinetic characterization of desulfovibrio gigas Hydrogenase upon selective chemical modification of amino acid groups as a tool for structure function relationships
Biochimica et Biophysica Acta, 2000Co-Authors: Antonio L De Lacey, E C Hatchikian, Elena Santamaria, Victor M FernandezAbstract:The effect of amino acid residues modification of Desulfovibrio gigas Hydrogenase on different activity assays is reported. The first method consisted in the modification of glutamic and aspartic acid residues of the enzyme with ethylenediamine in order to change the polarity of certain regions of the protein surface. The second method consisted in the modification of histidine residues with a Ru complex in order to change the acid-base properties of the histidine residues. The implication of these modifications in the enzyme kinetics has been studied by measuring in parallel the activities of para/ortho Hydrogen conversion, Deuterium/Hydrogen Exchange and dyes reduction with Hydrogen. Our experimental data support some hypothesis based on the three-dimensional structure of this enzyme: (a) electrostactic interactions between the Hydrogenase and the redox partner play an essential role in the kinetics; (b) the histidine ligand and the surrounding acidic residues of the distal [4Fe4S] cluster form the recognition site of the redox partner of the Hydrogenase; and (c) histidine residues are involved in the hydron transfer pathway of the Hydrogenase.
John Kuszewski - One of the best experts on this subject based on the ideXlab platform.
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Fast folding of a prototypic polypeptide: the immunoglobulin binding domain of streptococcal protein G.
Protein Science, 1994Co-Authors: John Kuszewski, G. Marius Clore, Angela M. GronenbornAbstract:The folding of the small (56 residues) highly stable B1 immunoglobulin binding domain (GB1) of streptococcal protein G has been investigated by quenched-flow Deuterium-Hydrogen Exchange. This system represents a paradigm for the study of protein folding because it exhibits no complicating features superimposed upon the intrinsic properties of the polypeptide chain. Collapse to a semicompact state exhibiting partial order, reflected in protection factors for ND-NH Exchange up to 10-fold higher than that expected for a random coil, occurs within the dead time (< or = 1 ms) of the quenched flow apparatus. This is followed by the formation of the fully native state, as monitored by the fractional proton occupancy of 26 backbone amide groups spread throughout the protein, in a single rapid concerted step with a half-life of 5.2 ms at 5 degrees C.
G. Marius Clore - One of the best experts on this subject based on the ideXlab platform.
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Fast folding of a prototypic polypeptide: the immunoglobulin binding domain of streptococcal protein G.
Protein Science, 1994Co-Authors: John Kuszewski, G. Marius Clore, Angela M. GronenbornAbstract:The folding of the small (56 residues) highly stable B1 immunoglobulin binding domain (GB1) of streptococcal protein G has been investigated by quenched-flow Deuterium-Hydrogen Exchange. This system represents a paradigm for the study of protein folding because it exhibits no complicating features superimposed upon the intrinsic properties of the polypeptide chain. Collapse to a semicompact state exhibiting partial order, reflected in protection factors for ND-NH Exchange up to 10-fold higher than that expected for a random coil, occurs within the dead time (< or = 1 ms) of the quenched flow apparatus. This is followed by the formation of the fully native state, as monitored by the fractional proton occupancy of 26 backbone amide groups spread throughout the protein, in a single rapid concerted step with a half-life of 5.2 ms at 5 degrees C.
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Kinetics of folding of the all-beta sheet protein interleukin-1 beta
Science, 1993Co-Authors: P Varley, Angela M. Gronenborn, H Christensen, Paul T. Wingfield, Roger H. Pain, G. Marius CloreAbstract:The folding of the all-beta sheet protein, interleukin-1 beta, was studied with nuclear magnetic resonance (NMR) spectroscopy, circular dichroism, and fluorescence. Ninety percent of the beta structure present in the native protein, as monitored by far-ultraviolet circular dichroism, was attained within 25 milliseconds, correlating with the first kinetic phase determined by tryptophan and 1-anilinonaphthalene-8-sulfonate fluorescence. In contrast, formation of stable native secondary structure, as measured by quenched-flow Deuterium-Hydrogen Exchange experiments, began after only 1 second. Results from the NMR experiments indicated the formation of at least two intermediates with half-lives of 0.7 to 1.5 and 15 to 25 seconds. The final stabilization of the secondary structure, however, occurs on a time scale much greater than 25 seconds. These results differ from previous results on mixed alpha helix-beta sheet proteins in which both the alpha helices and beta sheets were stabilized very rapidly (less than 10 to 20 milliseconds).