The Experts below are selected from a list of 54 Experts worldwide ranked by ideXlab platform
A. Podjarny - One of the best experts on this subject based on the ideXlab platform.
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Comparison of hydrogen determination with X-ray and neutron crystallography in a human aldose reductase–inhibitor complex
European Biophysics Journal, 2006Co-Authors: M. P. Blakeley, A. Mitschler, I. Hazemann, F. Meilleur, D. A. A. Myles, A. PodjarnyAbstract:Protonation states determination by neutron (2.2 Å at room temperature) and X-ray (0.66 Å at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW = 36 kDa), complexed with its NADP^+ Coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D_2O of the complex. We used the largest good-quality crystal (1.00 × 0.67 × 0.23 mm, i.e. volume of 0.15 mm^3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms ( B > 5 Å^2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.
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Comparison of hydrogen determination with X-ray and neutron crystallography in a human aldose reductase-inhibitor complex.
European biophysics journal : EBJ, 2006Co-Authors: M. P. Blakeley, A. Mitschler, I. Hazemann, F. Meilleur, D. A. A. Myles, A. PodjarnyAbstract:Protonation states determination by neutron (2.2 A at room temperature) and X-ray (0.66 A at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW=36 kDa), complexed with its NADP+ Coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D2O of the complex. We used the largest good-quality crystal (1.00x0.67x0.23 mm, i.e. volume of 0.15 mm3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms (B>5 A2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.
M. P. Blakeley - One of the best experts on this subject based on the ideXlab platform.
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Comparison of hydrogen determination with X-ray and neutron crystallography in a human aldose reductase–inhibitor complex
European Biophysics Journal, 2006Co-Authors: M. P. Blakeley, A. Mitschler, I. Hazemann, F. Meilleur, D. A. A. Myles, A. PodjarnyAbstract:Protonation states determination by neutron (2.2 Å at room temperature) and X-ray (0.66 Å at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW = 36 kDa), complexed with its NADP^+ Coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D_2O of the complex. We used the largest good-quality crystal (1.00 × 0.67 × 0.23 mm, i.e. volume of 0.15 mm^3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms ( B > 5 Å^2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.
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Comparison of hydrogen determination with X-ray and neutron crystallography in a human aldose reductase-inhibitor complex.
European biophysics journal : EBJ, 2006Co-Authors: M. P. Blakeley, A. Mitschler, I. Hazemann, F. Meilleur, D. A. A. Myles, A. PodjarnyAbstract:Protonation states determination by neutron (2.2 A at room temperature) and X-ray (0.66 A at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW=36 kDa), complexed with its NADP+ Coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D2O of the complex. We used the largest good-quality crystal (1.00x0.67x0.23 mm, i.e. volume of 0.15 mm3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms (B>5 A2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.
Milagros Medina - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of the active site architecture in plant-type ferredoxin-NADP(+) reductases catalytic complexes.
Biochimica et biophysica acta, 2014Co-Authors: Ana Sánchez-azqueta, Daniela L. Catalano-dupuy, Arleth López-rivero, María Laura Tondo, Elena G. Orellano, Eduardo A. Ceccarelli, Milagros MedinaAbstract:Abstract Kinetic isotope effects in reactions involving hydride transfer and their temperature dependence are powerful tools to explore dynamics of enzyme catalytic sites. In plant-type ferredoxin-NADP + reductases the FAD cofactor exchanges a hydride with the NADP(H) Coenzyme. Rates for these processes are considerably faster for the plastidic members (FNR) of the family than for those belonging to the bacterial class (FPR). Hydride transfer (HT) and deuteride transfer (DT) rates for the NADP + Coenzyme reduction of four plant-type FNRs (two representatives of the plastidic type FNRs and the other two from the bacterial class), and their temperature dependences are here examined applying a full tunnelling model with coupled environmental fluctuations. Parameters for the two plastidic FNRs confirm a tunnelling reaction with active dynamics contributions, but isotope effects on Arrhenius factors indicate a larger contribution for donor–acceptor distance (DAD) dynamics in the Pisum sativum FNR reaction than in the Anabaena FNR reaction. On the other hand, parameters for bacterial FPRs are consistent with passive environmental reorganisation movements dominating the HT coordinate and no contribution of DAD sampling or gating fluctuations. This indicates that active sites of FPRs are more organised and rigid than those of FNRs. These differences must be due to adaptation of the active sites and catalytic mechanisms to fulfil their particular metabolic roles, establishing a compromise between protein flexibility and functional optimisation. Analysis of site-directed mutants in plastidic enzymes additionally indicates the requirement of a minimal optimal architecture in the catalytic complex to provide a favourable gating contribution.
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A STD-NMR study of the interaction of the Anabaena ferredoxin-NADP+ reductase with the Coenzyme.
Molecules (Basel Switzerland), 2014Co-Authors: Lara V. Antonini, José R. Peregrina, Jesús Angulo, Milagros Medina, Pedro M. NietoAbstract:Ferredoxin-NADP+ reductase (FNR) catalyzes the electron transfer from ferredoxin to NADP+ via its flavin FAD cofactor. To get further insights in the architecture of the transient complexes produced during the hydride transfer event between the enzyme and the NADP+ Coenzyme we have applied NMR spectroscopy using Saturation Transfer Difference (STD) techniques to analyze the interaction between FNRox and the oxidized state of its NADP+ Coenzyme. We have found that STD NMR, together with the use of selected mutations on FNR and of the non-FNR reacting Coenzyme analogue NAD+, are appropriate tools to provide further information about the the interaction epitope.
D. A. A. Myles - One of the best experts on this subject based on the ideXlab platform.
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Comparison of hydrogen determination with X-ray and neutron crystallography in a human aldose reductase–inhibitor complex
European Biophysics Journal, 2006Co-Authors: M. P. Blakeley, A. Mitschler, I. Hazemann, F. Meilleur, D. A. A. Myles, A. PodjarnyAbstract:Protonation states determination by neutron (2.2 Å at room temperature) and X-ray (0.66 Å at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW = 36 kDa), complexed with its NADP^+ Coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D_2O of the complex. We used the largest good-quality crystal (1.00 × 0.67 × 0.23 mm, i.e. volume of 0.15 mm^3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms ( B > 5 Å^2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.
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Comparison of hydrogen determination with X-ray and neutron crystallography in a human aldose reductase-inhibitor complex.
European biophysics journal : EBJ, 2006Co-Authors: M. P. Blakeley, A. Mitschler, I. Hazemann, F. Meilleur, D. A. A. Myles, A. PodjarnyAbstract:Protonation states determination by neutron (2.2 A at room temperature) and X-ray (0.66 A at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW=36 kDa), complexed with its NADP+ Coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D2O of the complex. We used the largest good-quality crystal (1.00x0.67x0.23 mm, i.e. volume of 0.15 mm3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms (B>5 A2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.
F. Meilleur - One of the best experts on this subject based on the ideXlab platform.
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Comparison of hydrogen determination with X-ray and neutron crystallography in a human aldose reductase–inhibitor complex
European Biophysics Journal, 2006Co-Authors: M. P. Blakeley, A. Mitschler, I. Hazemann, F. Meilleur, D. A. A. Myles, A. PodjarnyAbstract:Protonation states determination by neutron (2.2 Å at room temperature) and X-ray (0.66 Å at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW = 36 kDa), complexed with its NADP^+ Coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D_2O of the complex. We used the largest good-quality crystal (1.00 × 0.67 × 0.23 mm, i.e. volume of 0.15 mm^3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms ( B > 5 Å^2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.
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Comparison of hydrogen determination with X-ray and neutron crystallography in a human aldose reductase-inhibitor complex.
European biophysics journal : EBJ, 2006Co-Authors: M. P. Blakeley, A. Mitschler, I. Hazemann, F. Meilleur, D. A. A. Myles, A. PodjarnyAbstract:Protonation states determination by neutron (2.2 A at room temperature) and X-ray (0.66 A at 100 K) crystallographic studies were compared for a medium size enzyme, human aldose reductase (MW=36 kDa), complexed with its NADP+ Coenzyme and a selected inhibitor of therapeutic interest. The neutron resolution could be achieved only with the ab initio fully deuterated protein and the subsequent crystallization in D2O of the complex. We used the largest good-quality crystal (1.00x0.67x0.23 mm, i.e. volume of 0.15 mm3) that we were able to grow so far. Both studies enable the determination of protonation states, with a clear advantage for neutrons in the case of less-ordered atoms (B>5 A2). Hydrogen atoms are best determined by a complementary analysis of the Fourier maps obtained from both methods.