Obdulio Lopez-Mayorga

Obdulio Lopez-Mayorga
University of Granada | UGR · Department of Physical Chemistry

About

39
Publications
1,516
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,516
Citations

Publications

Publications (39)
Article
The CD2AP and CIN85 adaptor proteins each employ three SH3 domains to cluster protein partners and ensure efficient signal transduction and downregulation of tyrosine kinase receptors. Using NMR, ITC and SAXS methods, we have characterized several binding modes of the N-terminal SH3 domain (SH3A) of CD2AP and CIN85 against two natural atypical prol...
Article
Full-text available
CD2 associated protein (CD2AP) is an adaptor protein that plays an important role in cell to cell union needed for the kidney function. CD2AP interacts, as an adaptor protein, with different natural targets, such as CD2, nefrin, c-Cbl and podocin. These proteins are believed to interact to one of the three SH3 domains that are positioned in the N-t...
Article
TtgR is the specific transcriptional repressor of the TtgABC efflux pump. TtgR and the TtgB efflux pump proteins possess multidrug-binding capacity, and their concerted action is responsible for the multidrug resistance phenotype of Pseudomonas putida DOT-T1E. TtgR binds to a pseudo-palindromic site that overlaps the ttgR/ttgA promoters. Dimethylsu...
Article
Site-directed mutagenesis has been used to produce local stability changes at two regions of the binding site surface of the alpha-spectrin SH3 domain (Spc-SH3) differing in their intrinsic stability. Mutations were made at residue 56, located at the solvent-exposed side of the short 3(10) helix, and at residue 21 in the tip of the flexible RT-loop...
Data
Thermodynamic analysis of protein-ligand binding using differential scanning calorimetry and two tables: Table 1: Ambiguous interaction restraints (AIR) and intermolecular NOE-derived distance restraints. Table 2: Apparent amide hydrogen-deuterium exchange rate constants and apparent Gibbs energies for the R21A Spc-SH3 domain at pH* 3.0 and 27.1°C,...
Article
Full-text available
SH3 domains are small protein modules of 60-85 amino acids that bind to short proline-rich sequences with moderate-to-low affinity and specificity. Interactions with SH3 domains play a crucial role in regulation of many cellular processes (some are related to cancer and AIDS) and have thus been interesting targets in drug design. The decapeptide AP...
Article
Steady-state flow-mix calorimetric methods require large amounts of sample and time to obtain data at variable reactant ratios. The use of continuous concentration gradients allows rapid generation of data with chemicals consumption comparable to other calorimetric techniques. An experimental set-up able to generate a linear concentration gradient...
Article
For the purpose of equilibrium and kinetic folding-unfolding studies, the SH3 domain of alpha-spectrin (spc-SH3) has long been considered a classic two-state folding protein. In this work we have indeed observed that the thermal unfolding curves of spc-SH3 measured at pH 3.0 by differential scanning calorimetry, circular dichroism, and NMR follow a...
Article
We have studied the effects produced by site-directed mutagenesis upon energetic and structural cooperativity in the Src homology region 3 domain of alpha-spectrin. The mutation of Asn47 to Gly or Ala in the distal loop brings about significant changes to the global stability of the domain in spite of not affecting its structure to any great extent...
Article
The amide hydrogen-deuterium exchange (HX) in the Src homology region 3 (SH3) domain of alpha-spectrin has been measured by nuclear magnetic resonance as a function of temperature between 8 and 46 degrees C. The analysis of the temperature dependence of HX from a statistical thermodynamic point of view has allowed us to estimate the enthalpies and...
Article
The amide hydrogen–deuterium exchange (HX) in the Src homology region 3 (SH3) domain of α-spectrin has been measured by nuclear magnetic resonance as a function of temperature between 8 and 46°C. The analysis of the temperature dependence of HX from a statistical thermodynamic point of view has allowed us to estimate the enthalpies and entropies of...
Article
Using nuclear magnetic resonance we have measured the hydrogen exchange (HX) in the Src homology region 3 (SH3) domain of alpha-spectrin as a function of pH*. At very acidic pH* values the exchange of most residues appears to occur via global unfolding, although several residues show abnormally large Gibbs energies of exchange, suggesting the prese...
Article
The connection of an LKB flow microcalorimetric unit. Model 2107, to a development system based on an M-6800 microcomputer is described. The microcalorimeter-microcomputer system can work under either open-loop or closed-loop control. The latter type of control results in the total automation of a whole set of isothermal measurements corresponding...
Article
Full-text available
Some specific advantages, such as the saving of both time and materials, are to be gained from carrying out measurements under dynamic conditions with instruments that are normally used for steady-state experiments. To do this, however, it is necessary first of all to determine the dynamic characteristics of the system. Thus, the dynamic characteri...
Article
In a previous article a comprehensive description of an isothermal titration microcalorimeter with Peltier compensation was reported. This work deals with the characterization procedure and the operation mode. The transfer function parameters (time constants, calibration constants, and thermal properties of the system components) have been determin...
Article
A detailed description of a differential isothermal titration microcalorimeter with Peltier compensation is reported here. It can be considered as a heat flux or conduction microcalorimeter with dynamic power compensation. The design, based on the twin principle, is very simple and the manufacture is of low cost and complexity. The system operation...
Article
Full-text available
An old problem in Isothermal Titration Calorimetry is the accurate characterisation of the instrument, i.e. the determination of the instrumental transfer function. Normally, this calibration is performed electrically or through well known chemical reactions, but the transfer function parameters obtained by both methods generally do not agree: the...
Article
The folding/unfolding equilibrium of the alpha-spectrin SH3 domain has been measured by NMR-detected hydrogen/deuterium exchange and by differential scanning calorimetry. Protection factors against exchange have been obtained under native conditions for more than half of the residues in the domain. Most protected residues are located at the beta-st...
Article
For part I see El Harrous et. al., ibid., vol.5, pp.1065-70 (1994). This paper continues the description of an isothermal titration calorimeter already outlined in the previous paper. We have determined its thermal parameters and report here on the performance of the calorimeter and the method of measuring via electrical compensation of the thermal...
Article
A theoretical analysis in Laplace's transformed domain based on a power balance represents a suitable model for an isothermal titration calorimeter with dynamic power compensation, designed and implemented in our laboratory. A rigorous calibration of the injection system and the calorimetric response was also made. Using electrically generated heat...
Article
This paper introduces a new measuring method in Isothermal Titration Calorimetry (ITC). This method, based on a proportional-integral control system, offers many important advantages when compared to the frequently used proportional control: higher signal-to-noise ratio, improved stability of baseline, increased static and dynamic sensitivity, simi...
Article
Full-text available
The binding of adenosine 5′-monophosphate to liver glycogen phosphorylase a (EC 2.4.1.1) has been studied by size exclusion high performance liquid chromatography and isothermal titration microcalorimetry at pH 6.9 over a temperature range of 25 to 35°C. The results are compared with those of the binding of the same nucleotide to the muscle isozyme...
Article
A structural parameterization of the folding energetics has been used to predict the effect of single amino acid mutations at exposed locations in alpha-helices. The results have been used to derive a structure-based thermodynamic scale of alpha-helix propensities for amino acids. The structure-based thermodynamic analysis was performed for four di...
Article
The energetics of the interaction between liver glycogen phosphorylase b and the adenosine 5'-monophosphate (AMP) have been studied by equilibrium dialysis and isothermal titration calorimetry (ITC) at 25 degrees C. A concomitant net release of protons with AMP to phosphorylase binding was detected carrying out calorimetric experiments in three buf...
Article
The binding of 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP) to Lactobacillus casei recombinant thymidylate synthase has been studied by isothermal titration microcalorimetry at pH 7.1 over the temperature range 16-35 degrees C. Calorimetric measurements in various buffer systems with different heats of ionization suggest that a proton uptake i...
Article
Multifrequency calorimetry is a technique aimed at measuring directly the dynamics of the energetic events that take place during a thermally induced transition by measuring the frequency dispersion of the heat capacity. This is done by modulating the conformational equilibrium using a small oscillatory temperature perturbation (≈0.05–0.1°C) center...
Article
A marked temperature dependence of the 13C and 15N chemical shifts of 3-hydroxypyridine in D2O (pD = 7.0) was observed. This dependence is explained in terms of thermally induced equilibrium shifts between the neutral form and the zwitterionic form of 3-hydroxypyridine. A method was developed to characterize the thermodynamics of the equilibria tha...
Article
The thermal behaviour of bovine-brain myelin membrane has been studied by high-sensitivity differential scanning calorimetry, Fourier-transform infrared spectroscopy and thermal gel analysis. Spectroscopic results indicate that protein transitions take place between 60 degrees C and 90 degrees C, while thermal gel analysis has provided the thermal...
Article
Full-text available
The folding-unfolding transition of Fe(III) cytochrome c has been studied with the new technique of multifrequency calorimetry. Multifrequency calorimetry is aimed at measuring directly the dynamics of the energetic events that take place during a thermally induced transition by measuring the frequency dispersion of the heat capacity. This is done...
Article
Full-text available
A multifrequency calorimeter has been designed to measure the amplitude and time regime of the enthalpic fluctuations associated with structural or conformational transitions in biological macromolecular systems. The heat capacity function at constant pressure is directly proportional to the magnitude of the enthalpic fluctuations in a system. Biol...
Article
The interactions of the targeting sequence of the mitochondrial enzyme ornithine transcarbamylase with phospholipid bilayers of different molecular compositions have been studied by high-sensitivity heating and cooling differential scanning calorimetry, high-sensitivity isothermal titration calorimetry, fluorescence spectroscopy, and electron micro...
Article
The apparent heat capacity function measured by high-sensitivity differential scanning calorimetry contains dynamic components of two different origins: (1) an intrinsic component arising from the finite instrument time response; and (2) a sample component arising from the kinetics of the thermal transition under study. The intrinsic instrumental c...
Article
Full-text available
The binding of AMP to rabbit muscle glycogen phosphorylase a (EC 2.4.1.1.) has been studied by equilibrium dialysis and isothermal microcalorimetry at pH 6.9 over a temperature range of 25 degrees C to 35 degrees C. Thermal titration experiments were carried out in various buffer systems. We have found by these methods that a certain number of prot...
Article
Full-text available
The binding of AMP to rabbit muscle glycogen phosphorylase a (EC 2.4.1.1.) has been studied by equilibrium dialysis and isothermal microcalorimetry at pH 6.9 over a temperature range of 25 degrees C to 35 degrees C. Thermal titration experiments were carried out in various buffer systems. We have found by these methods that a certain number of prot...
Article
Full-text available
Reaction microcalorimetry and equilibrium dialysis have been used to study the binding of AMP and IMP to glycogen phosphorylase b (EC 2.4.1.1) at 25 degrees C and pH 6.9. The combination of both techniques has enabled us to obtain some of the thermodynamic parameters for these binding processes. Four binding sites were found to be present in the di...

Network

Cited By