Jesús Salgado

Jesús Salgado
University of Valencia | UV · Instituto de Ciencia Molecular (ICMol)

PhD

About

108
Publications
6,716
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2,726
Citations
Citations since 2017
3 Research Items
682 Citations
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140
2017201820192020202120222023020406080100120140

Publications

Publications (108)
Article
Full-text available
The spontaneous insertion of helical transmembrane (TM) polypeptides into lipid bilayers is driven by three sequential equilibria: solution-to-membrane interface (MI) partition, unstructured-to-helical folding, and MI-to-TM helix insertion. A bottleneck for understanding these three steps is the lack of experimental approaches to perturb membrane-b...
Preprint
Full-text available
According to the three-step model, the spontaneous insertion and folding of helical transmembrane (TM) polypeptides into lipid bilayers is driven by three sequential equilibria: solution-to-membrane interface (MI) partition, unstructured-to-helical folding, and MI-to-TM helix insertion. However, understanding these three steps with molecular detail...
Article
Full-text available
The large plasticity, dynamics and adaptability of biological membranes allow different modes of intrinsic and inducible permeability. These phenomena are of physiological importance for a number of natural functions related to cell death and can also be manipulated artificially for practical purposes like gene transfer, drug delivery, prevention o...
Article
Full-text available
The large variety of antimicrobial peptide databases developed to date is characterized by a substantial overlap of data and similarity of sequences. Our goals are to analyze the levels of redundancy for all available antimicrobial peptide databases and use this information to build a new non-redundant sequence database. For this purpose , a new so...
Article
Melittin is the most studied membrane-active peptide and archetype within a large and diverse group of pore-formers. However, the molecular characteristics of melittin pores remain largely unknown. Here we show by atomic force microscopy (AFM) that lipid monolayers in presence of melittin are decorated by numerous regularly shaped circular pores, w...
Article
Melittin is the most studied membrane-active peptide and archetype within a large and diverse group of pore formers. However, the molecular characteristics of melittin pores remain largely unknown. Herein, we show by atomic force microscopy (AFM) that lipid monolayers in the presence of melittin are decorated with numerous regularly shaped circular...
Article
Kinetics is a key aspect of the renowned protein folding problem. Here, we propose a comprehensive approach to folding kinetics where a polypeptide chain is assumed to behave as an elastic material described by the Hooke's law. A novel parameter called elastic-folding constant results from our model and is suggested to distinguish between protein w...
Article
Many amphiphilic antimicrobial peptides permeabilize bacterial membranes via successive steps of binding, re-alignment and/or oligomerization. Here, we have systematically compared the lipid interactions of two structurally unrelated peptides: the cyclic β-pleated gramicidin S (GS), and the α-helical PGLa. (19)F-NMR was used to screen their molecul...
Article
In biological membranes the alignment of embedded proteins provides crucial structural information. The transmembrane (TM) parts have well-defined secondary structures, in most cases α-helices and their orientation is given by a tilt angle and an azimuthal rotation angle around the main axis. The tilt angle is readily visualized and has been found...
Article
Full-text available
The principles governing protein folding stand as one of the biggest challenges of Biophysics. Modeling the global stability of proteins and predicting their tertiary structure are hard tasks, due in part to the variety and large number of forces involved and the difficulties to describe them with sufficient accuracy. We have developed a fast, phys...
Article
Full-text available
The present study describes the synthesis of nanoparticles of silver-gold alloys and with their electrokinetic and spectroscopic characterisation. The synthesis was made in two steps. In the first step silver nanoparticles coated with silica (Ag@SiO2) were synthesised using a novel method assisted by laser ablation. The second step consisted on the...
Article
Full-text available
Electrophoretic mobility and ζ-potential are important physical parameters for the characterization of micro- and nanosystems. In this communication we describe a new method for determining the ζ-potential through the assembly of two well known techniques: free electrophoresis and Dynamic Speckle. When coherent light passes through a fluid having s...
Article
Full-text available
Anti-apoptotic Bfl-1 and pro-apoptotic Bax, two members of the Bcl-2 family sharing a similar structural fold, are classically viewed as antagonist regulators of apoptosis. However, both proteins were reported to be death inducers following cleavage by the cysteine protease µ-calpain. Here we demonstrate that calpain-mediated cleavage of full-lengt...
Data
Ectopic expression GFP-tagged C-terminal fragments of Bax and Bfl-1 induces cell death in wt and DKO MEF cells. Graphs showing cell death (bottom panel) measured by Annexin-V staining of MEF and MEF-DKO cells expressing the different GFP-tagged constructs described in the upper panel. GFP-tranfected cells treated with staurosporine (STS) or left un...
Data
Sequence of oligonucleotide primers used for this study. (TIF)
Data
µ-calpain resistant mutants of Bfl-1 have a toxic effect when expressed in Hela cells. Top panels: Hela cells were transfected with GFP-tagged Bfl-1 constructs (wt, DD or SD) and fluorescence was observed using an inverted microscope 20 hours post transfection. Images are representative of the total field. Middle panels: quantification by FACS of t...
Data
SDS-PAGE patterns of products from µ-calpain-treated GST-Bfl-1(1–151) and GST-Bfl-1(1–172). Recombinant full length Bfl-1(1–172) and C-terminal truncated Bfl-1(1–151) were treated with µ-calpain in vitro and cleaved products were separated by SDS-PAGE. Predominant C-terminal truncated product due to cleavage at F71/N72 site is detected (black arrow...
Data
Identification of the Bfl-1 homologous sequence in BCL2L10 overlapping the first μ-calpain site. Alignment of Bfl-1 and Bcl2L10 N-terminal primary sequences. Homologous sequences in Bcl2L10 surrounding the first cleavage site of Bfl-1 was determined (Box) to design Bfl-1 swapped mutant (Bfl-1SD). The disordered strech following alpha 1 helix of Bfl...
Data
Sequence of synthetic peptides used for this study. (TIF)
Article
Many solid-state nuclear magnetic resonance (NMR) approaches for membrane proteins rely on orientation-dependent parameters, from which the alignment of peptide segments in the lipid bilayer can be calculated. Molecules embedded in liquid-crystalline membranes, such as monomeric helices, are highly mobile, leading to partial averaging of the measur...
Article
Hydrophobic mismatch still represents a puzzle for transmembrane peptides, despite the apparent simplicity of this concept and its demonstrated validity in natural membranes. Using a wealth of available experimental ((2))H NMR data, we provide here a comprehensive explanation of the orientation and dynamics of model peptides in lipid bilayers, whic...
Article
Full-text available
The enhancement of the electromagnetic field in the surroundings of nanoparticles via surface plasmon resonance offers promising possibilities for biomedical applications. Here we report on the selective triggering of antibacterial activity using a new type of silver nanoparticles coated with silica, Ag@silica, irradiated at their surface plasmon f...
Article
Full-text available
Although lipid membranes serve as effective sealing barriers for the passage of most polar solutes, nonmediated leakage is not completely improbable. A high activation energy normally keeps unassisted bilayer permeation at a very low frequency, but lipids are able to self-organize as pores even in peptide-free and protein-free membranes. The probab...
Article
Full-text available
Although many cancer cells are primed for apoptosis, they usually develop resistance to cell death at several levels. Permeabilization of the outer mitochondrial membrane, which is mediated by proapoptotic Bcl-2 family members such as Bax, is considered as a point of no return for initiating apoptotic cell death. This crucial role has placed Bcl-2...
Article
Here we report on the triggering of antibacterial activity by a new type of silver nanoparticle coated with porous silica, Ag@silica, irradiated at their surface plasmon resonant frequency. The nanoparticles are able to bind readily to the surface of bacterial cells, although this does not affect bacterial growth since the silica shell largely atte...
Article
Pores made by amphipathic cationic peptides (e.g., antimicrobials and fragments of pore-forming proteins) are typically studied by examining the kinetics of vesicle leakage after peptide addition or obtaining structural measurements in reconstituted peptide-lipid systems. In the first case, the pores have been considered transient phenomena that al...
Data
Full-text available
Plots of surface pressure versus time for the different peptides used in the study. Records #1 and #2 refer to duplicate experiments, carried out using a fresh film and subphase. The different steps of the experiment are shown across the second plot (BAX-α1 POPC/DOPE/CL). Lipids used for forming the monolayer are first deposited (d; the arrow marks...
Data
BAM images for control peptides BAX-α1 and BCL2L10-LAAS with POPC/DOPE or POPC/DOPE/CL lipids. See Figure S3 for surface pressure-time isotherms. BAX-α1 (of sequence EQIMKTGAFLLQGFIQDRAGRW) corresponds to the first helix localized at the N-terminus of BAX. BCL2L10-LAAS corresponds to the connecting region between predicted α5-α6 helices of BCL2L10,...
Data
BAM images acquired at initial surface pressures of 5 mN/m or 30 mN/m for BAX-α5S and BCLX-α5S. The BAM images of MOM and MIM/MOM-like lipid monolayers were recorded before (right) and after (left) addition of 0.2 µM BAX-α5S or BCLX-α5S into the subphase. (10.20 MB TIF)
Article
Full-text available
The BCL-2 family of proteins includes pro- and antiapoptotic members acting by controlling the permeabilization of mitochondria. Although the association of these proteins with the outer mitochondrial membrane is crucial for their function, little is known about the characteristics of this interaction. Here, we followed a reductionist approach to c...
Article
The functional state of a membrane-active peptide is often defined by its conformation, molecular orientation, and its oligomeric state in the lipid bilayer. These “static” structural properties can be routinely studied by solid state NMR using isotope-labeled peptides. In the highly dynamic environment of a liquid crystalline biomembrane, however,...
Patent
Full-text available
he present invention relates to the use of nanoparticles with a silver central core and inert outer coating for inducing cell death in a controlled manner. The invention likewise relates to the method required for performing said cytotoxic process, which involves laser irradiation at a wavelength close to the SPR absorption maximum of the nanoparti...
Article
Bilayer lipids, far from being passive elements, have multiple roles in polypeptide-dependent pore formation. Lipids participate at all stages of the formation of pores by providing the binding site for proteins and peptides, conditioning their active structure and modulating the molecular reorganization of the membrane complex. Such general functi...
Article
The proteins of the Bcl-2 family regulate the release of the apoptotic factors from mitochondria during apoptosis, a key event in physiological cell death. Although their molecular mechanisms remain unclear, the Bcl-2 proteins have been proposed to directly control the permeability of the outer mitochondrial membrane by pore formation. Indeed, they...
Article
Unlike soluble proteins, membrane polypeptides face an anisotropic milieu. This imposes restraints on their orientation and provides a reference that makes structure prediction tractable by minimalistic thermodynamic models. Here we use this framework to build orientational distributions of monomeric membrane-bound peptides and to predict their exp...
Article
The asymmetric insertion of amphiphiles into biological membranes compromises the balance between the inner and outer monolayers. As a result, area expansion of the receiving leaflet and curvature strain may lead to membrane permeation, shape changes, or membrane fusion events. We have conducted both atomistic and coarse-grained molecular dynamics...
Article
Solid-state (2)H-NMR is routinely used to determine the alignment of membrane-bound peptides. Here we demonstrate that it can also provide a quantitative measure of the fluctuations around the distinct molecular axes. Using several dynamic models with increasing complexity, we reanalyzed published (2)H-NMR data on two representative alpha-helical p...
Article
Membrane proteins and peptides exhibit a preferred orientation in the lipid bilayer while fluctuating in an anisotropic manner. Both the orientation and the dynamics have direct functional implications, but motions are usually not accessible, and structural descriptions are generally static. Using simulated data, we analyze systematically the impac...
Article
Amphipathic membrane-active peptides (antimicrobial, hemolytic, cell-penetrating, fusogenic, etc.) achieve their functions by distinct interaction with lipid bilayers. Some typical structural modes are described in terms of models like the “barrel stave”, “toroidal pore”, “carpet” etc. These models are related to the alignment states of the peptide...
Article
Full-text available
The basic physical rules underlying the organization of biological membranes can be gathered under the simple, but powerful, concept of hydrophobic mismatch. For example, the mutual adjustment of the lipid and protein hydrophobic lengths can be related with the existence of lipid rafts and explain discrete secretory pathways in the Golgi apparatus....
Article
By isotope labeling of membrane-bound peptides, typically with 2H, 19F, or 15N, solid-state NMR experiments can yield data from which the orientation of peptides in a native membrane environment can be determined. Such an orientation is defined by a tilt angle and an azimuthal rotation angle.Here we show that to obtain correct values of the orienta...
Article
Full-text available
Bax is a proapoptotic protein implicated in the release of cell-death activating factors from the mitochondrial intermembrane space. Although the structure of the membrane-bound forms of Bax is unknown, it has been proposed to form proteolipidic pores. Studies with synthetic lipid vesicles have shown that fragments encompassing helix-5 of Bax retai...
Article
This article describes a strategy to develop, starting from a de novo design, bivalent peptides containing two different (alpha-helix and beta-hairpin) and independent secondary-structure elements. The design was based on the use of conformationally restricted peptide libraries. Structural characterization by NMR revealed that the peptides were sta...
Article
Antimicrobial peptides can kill bacteria by permeabilizing their cell membrane, as these amphiphilicmolecules interact favourably with lipid bilayers. This mechanism of action is attributed eitherto the formation of a peptide "carpet" on the membrane surface, or to a transmembranepore. However, the structure of such a pore has not yet been resolved...
Patent
Full-text available
The present invention relates to the use of nanoparticles with a silver central core and inert outer coating for inducing cell death in a controlled manner. The invention likewise relates to the method required for performing said cytotoxic process, which involves laser irradiation at a wavelength close to the SPR absorption maximum of the nanopart...
Article
The structural organization in a peptide/membrane supramolecular complex is best described by knowledge of the peptide orientation plus its time-dependent and spatial fluctuations. The static orientation, defined by the peptide tilt and a rotation about its molecular axis, is accessible through a number of spectroscopic methods. However, peptide dy...
Article
Bax is a critical regulator of physiological cell death that increases the permeability of the outer mitochondrial membrane and facilitates the release of the so-called apoptotic factors during apoptosis. The molecular mechanism of action is unknown, but it probably involves the formation of partially lipidic pores induced by Bax. To investigate th...
Article
Full-text available
Our project for iGEM 2006 consisted of designing a cellular vanillin biosensor. We used an EnvZ-E. coli strain as a chassis, and constructed two different devices: a sensor and an actuator, assembled using OmpR-P as a standardised mediator. The sensor device contained a computationally designed vanillin receptor and a synthetic two-component signal...
Article
Model biological membranes consisting of peptide/lipid-bilayer complexes can nowadays be studied by classical molecular dynamics (MD) simulations at atomic detail. In most cases, the simulation starts with an assumed state of a peptide in a preformed bilayer, from which equilibrium configurations are difficult to obtain due to a relatively slow mol...
Article
Surfactant protein C (SP-C) is an essential component for the surface tension-lowering activity of the pulmonary surfactant system. It contains a valine-rich α helix that spans the lipid bilayer, and is one of the most hydrophobic proteins known so far. SP-C is also an essential component of various surfactant preparations of animal origin currentl...
Article
Proteins of the B-cell lymphoma protein 2 (Bcl2) family are key regulators of the apoptotic cascade, controlling the release of apoptotic factors from the mitochondrial intermembrane space. A helical hairpin found in the core of water-soluble folds of these proteins has been reported to be the pore-forming domain. Here we show that peptides includi...
Article
Full-text available
The current model for cell-to-cell movement of plant viruses holds that transport requires virus-encoded movement proteins that intimately associate with endoplasmic reticulum membranes. We have examined the early stages of the integration into endoplasmic reticulum membranes of a double-spanning viral movement protein using photocross-linking. We...
Article
Bax and Bid are proapoptotic proteins of the Bcl-2 family that regulate the release of apoptogenic factors from mitochondria. Although they localize constitutively in the cytoplasm, their apoptotic function is exerted at the mitochondrial outer membrane, and is related to their ability to form transbilayer pores. Here we report the poration activit...
Article
Apoptosis regulators of the Bcl-2 family associate with intracellular membranes from mitochondria and the endoplasmic reticulum, where they perform their function. The activity of these proteins is related to the release of apoptogenic factors, sequestered in the mitochondria, to the cytoplasm, probably through the formation of ion and/or protein t...
Article
Integral membrane proteins often contain proline residues in their alpha-helical transmembrane (TM) fragments, which may strongly influence their folding and association. Pro-scanning mutagenesis of the helical domain of glycophorin A (GpA) showed that replacement of the residues located at the center abrogates helix packing while substitution of t...
Article
Apoptosis is a complex process that plays a central role in physiological and pathological cell death. This fast evolving research area has experienced incredible development in the past few years. Progress in the knowledge of the structure of many of the main molecular actors of the apoptotic signal transduction pathways has driven the design of s...
Article
Full-text available
The antimicrobial properties of the cyclic -sheet peptide gramicidin S are attributed to its destabilizing effect on lipid membranes. Here we present the membrane-bound structure and alignment of a derivative of this peptide, based on angular and distance constraints. Solid-state 19F-NMR was used to study a 19F-labelled gramicidin S analogue in dim...
Chapter
Structure determination of membrane-associated polypeptides presents one of the major challenges to solid state NMR spectroscopy. Many studies have been carried out so far using selective isotope labels, such as 2H, 13C, or 15N[1]. These NMR-reporters can be incorporated into the protein backbone or side chains, to reveal local structural parameter...
Article
A scaled-up isolation and purification procedure is described for tyrosinase from Streptomyces antibioticus. Kinetic studies of the enzyme catalysed conversion of l-3,4-dihydroxyphenylalanine (l-DOPA) into DOPAchrome show that kojic acid, l-mimosine, p-toluic acid and benzoic acid exhibit competitive inhibition with inhibition constants of 3.4, 30,...
Article
1H- and 13C-NMR spectroscopy is applied to investigate the CuA and type 1 active sites of copper proteins in solution. The analysis of hyperfine shifted 1H resonances allows the comparison of the electron spin density delocalization in the CuA site of the wild-type soluble domains of various cytochrome c oxidases (Thermus thermophilus, Paracoccus d...
Article
The paramagnetic 1H NMR spectra of the Co(II) and Ni(II) substituted forms of the type 1 blue copper protein (cupredoxin) amicyanin have been assigned. This is the first such analysis of a cupr