A5080918059- Lipid Membrane Structure and Behavior
- Protein Structure and Dynamics
- Protein Interaction Studies and Fluorescence Analysis
- Ion Transport and Channel Regulation
- ATP Synthase and ATPases Research
- Erythrocyte Function and Pathophysiology
- Drug Transport and Resistance Mechanisms
- Trace Elements in Health
- Membrane-based Ion Separation Techniques
- Cellular transport and secretion
- Hemoglobin structure and function
- Mitochondrial Function and Pathology
- RNA and protein synthesis mechanisms
- Pancreatic function and diabetes
- Environmental Monitoring and Data Management
- Glycosylation and Glycoproteins Research
- Spectroscopy and Quantum Chemical Studies
- Scientific Computing and Data Management
- Advanced Glycation End Products research
- Photosynthetic Processes and Mechanisms
- Ion channel regulation and function
- Neonatal Health and Biochemistry
- Genetics, Bioinformatics, and Biomedical Research
- Bacterial Infections and Vaccines
- Biochemical Analysis and Sensing Techniques
University of Buenos Aires
2016-2025
Consejo Nacional de Investigaciones Científicas y Técnicas
2015-2024
Instituto de Química y Fisicoquímica Biológicas
2015-2024
Universidad Nacional de La Plata
1997
Biochemistry Research Institute of La Plata
1990
Cooperative binding is one of the most interesting and not fully understood phenomena involved in control regulation biological processes. Here we analyze simplest phenomenological model that can account for cooperativity (i.e. ligand to a macromolecule with two sites) by generating equilibrium isotherms from deterministically simulated time courses. We show Hill coefficients determined cooperative binding, provide good measure Gibbs free energy interaction among sites, their values are...
Abstract This work describes a laboratory experiment to illustrate the usefulness of fluorescence anisotropy in field biophysics. Fluorescence dansyl‐labeled BSA was determined media increasing glycerol concentrations. The Perrin equation fitted experimental data, obtaining molecular volume protein. simplicity and data analysis helped students focus on relationship between probe rotational diffusion. Additionally, this exercise has advantage using protein that are inexpensive very common...
Lateral organization of biological membranes is frequently studied using fluorescence microscopy. One the most widely used probes for these studies 2-dimethylamino-6-lauroylnaphthalene (laurdan). The this probe sensitive to environment polarity, and thus laurdan reports local penetration water when inserted in membranes. Unfortunately, can only be under two-photon excitation due its low photostability. This a very important limitation, because there are not too many laboratories with...
Abstract Membrane transporters are essential for cell homeostasis. Among them P-type ATPases, which couple ATP hydrolysis to solute transport, play a key role. Despite extensive research, the fine mechanisms by this coupling occurs not completely understood. In work, we analyzed effect of substrate, temperature, and urea on steady state ATPase activity, tryptophan fluorescence far-UV ellipticity catalytic domain thermophilic Cu(I) transport ATPase. Through local frustration analysis in...
Fluorescence is one of the most widely used techniques in biological sciences. Its exceptional sensitivity and versatility make it a tool first choice for quantitative studies biophysics. The concept phasors, originally introduced by Charles Steinmetz late 19th century analyzing alternating current circuits, has since found applications across diverse disciplines, including fluorescence spectroscopy. main idea behind phasors was posited Gregorio Weber 1981. By complementary nature pulse...
Erythrocyte membranes drawn from diabetic patients with poor metabolic control have increased protein glycosylation and decreased Ca2(+)-ATPase activity. A significant relationship was found between these two parameters. Similar results were obtained when activity measured in normal erythrocytes preincubated glucose. In this condition, both parameters showed a clear time dose dependence. Incubation of erythrocyte instead intact glucose glucose-6-phosphate strongly suggests that only the...
Non-enzymatic glycation of biomolecules has been implicated in the pathophysiology aging and diabetes. Among potential targets for are biological membranes, characterized by a complex organization lipids proteins interacting forming domains different size stability. In present study, we analyse effects on interactions between membrane lipids. The phospholipid affinity transmembrane surface PMCA (plasma-membrane Ca(2+)-ATPase) was determined after incubating protein or phospholipids with...
In a previous paper we demonstrated that incubation of either intact erythrocytes or membranes with glucose decreases the activity membrane Ca(2+)-ATPase [González Flecha, Bermúdez, Cédola, Gagliardino and Rossi (1990) Diabetes 39, 707-711]. The aim present work was to obtain information about mechanism this inhibition. For purpose, experiments were carried out purified Ca(2+)-ATPase, inside-out vesicles from human erythrocytes. Incubation led decay in enzyme up 50% control under conditions...
Semen rheology was studied to elucidate the biochemical basis of seminal plasma hyperviscosity. proved fit in with a power law model, by presenting pseudoplastic behavior. Apparent viscosity at 230 s(-1) and 25 degrees C (eta(a)) 4.3 /- 0.2 cp 5.4 +/- 0.4 normal high-consistency semen, respectively. The effect enzymes mucolytic agents on human were evaluated incubating hyperviscous semen pool aliquots trypsin, dithiothreitol, EDTA, alpha-amylase deoxyribonuclease I. After incubation, trypsin...
The effects of lipids on membrane proteins are likely to be complex and unique for each protein. Here we studied different detergent/phosphatidylcholine reconstitution media tested their plasma Ca(2+) pump (PMCA). We found that Ca(2+)-ATPase activity shows a biphasic behavior with respect the ratio. Moreover, maximal largely depends length unsaturation degree hydrocarbon chain. Using static light scattering fluorescence correlation spectroscopy, monitored changes in hydrodynamic radius...
Lipid-protein interactions play an essential role in the regulation of biological function integral membrane proteins; however, underlying molecular mechanisms are not fully understood. Here we explore modulation by phospholipids enzymatic activity plasma calcium pump reconstituted detergent-phospholipid mixed micelles variable composition. The presence increasing quantities produced a cooperative increase ATPase enzyme. This activation effect was reversible and depended on...
Peroxiredoxins (Prxs) constitute a ubiquitous family of Cys-dependent peroxidases that play essential roles in reducing hydrogen peroxide, peroxynitrite, and organic hydroperoxides almost all organisms. Members the Prx subfamilies show differential oxidizing substrate specificities await explanations at molecular level. Among them, alkyl hydroperoxide reductases E (AhpE) is novel subfamily comprising Mycobacterium tuberculosis AhpE AhpE-like proteins expressed some bacteria archaea. We...