Size and conformational features of ErbB2 and ErbB3 receptors: a TEM and DLS comparative study

Vicente-Alique, Ernesto; Núñez-Ramírez, Rafael; Vega, Juan Francisco; Hu, Ping; Martínez‐Salazar, Javier

doi:10.1007/s00249-011-0699-y

Cited by 12 publications

(8 citation statements)

References 30 publications

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“…By fitting the data obtained for bare nanoprobes (red markers) and for nanoprobes with a fully assembled analyte shell (blue markers), we deduced average shell thicknesses of 15 ± 9.5 nm for the antibody functionalization and 25 ± 13 nm for the antibody layer with bound target proteins. These values correlate well with reported IgG antibody and sHER2 protein sizes. For target protein analysis, the actual measurement signal is defined by the difference in phase lag angles between bare nanoprobes and nanoprobes with bound analyte.…”

Section: Resultssupporting

confidence: 87%

“…The analyte was added together with a 75-fold higher concentration of bovine serum albumin (BSA) protein, which when added alone did not alter the nanoprobe signal (green markers), thus confirming specific sHER2 binding. By fitting the data obtained for bare nanoprobes (red markers) and for nanoprobes with a fully assembled analyte shell (blue markers), we deduced average shell thicknesses of 15 ± 9.5 nm for the antibody functionalization and 25 ± 19 and sHER2 protein 20 sizes. For target protein analysis, the actual measurement signal is defined by the difference in phase lag angles between bare nanoprobes and nanoprobes with bound analyte.…”

Section: Resultsmentioning

confidence: 99%

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Homogeneous Protein Analysis by Magnetic Core–Shell Nanorod Probes

Schrittwieser

Pelaz

Parak

et al. 2016

ACS Appl. Mater. Interfaces

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Studying protein interactions is of vital importance both to fundamental biology research and to medical applications. Here, we report on the experimental proof of a universally applicable labelfree homogeneous platform for rapid protein analysis. It is based on optically detecting changes in the rotational dynamics of magnetically agitated core-shell nanorods upon their specific interaction with proteins. By adjusting the excitation frequency, we are able to optimize the measurement signal for each analyte protein size. In addition, due to the locking of the optical signal to the magnetic excitation frequency, background signals are suppressed, thus allowing exclusive studies of processes at the nanoprobe surface only. We study target proteins (soluble domain of the human epidermal growth factor receptor 2 -sHER2) specifically binding to antibodies (trastuzumab) immobilized on the surface of our nanoprobes and demonstrate direct deduction of their respective sizes. Additionally, we examine the dependence of our measurement signal on the concentration of the analyte protein, and deduce a minimally detectable sHER2 concentration of 440 pM. For our homogeneous measurement platform, good dispersion stability of the applied nanoprobes under physiological conditions is of vital importance. To that end, we support our measurement data by theoretical modeling of the total particle-particle interaction energies. The successful implementation of our platform offers scope for applications in biomarker-based diagnostics as well as for answering basic biology questions.

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Section: Resultssupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Homogeneous Protein Analysis by Magnetic Core–Shell Nanorod Probes

Schrittwieser

Pelaz

Parak

et al. 2016

ACS Appl. Mater. Interfaces

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“…Fitting of the experimental data (solid lines in the figure) by the respective theoretical model [ 299 ] resulted in hydrodynamic shell thicknesses of 15 ± 9.5 nm for the antibody shell and of 25 ± 13 nm for the antibody shell including bound target protein (both measured on top of the nanoreagents). These values are in good agreement with respective protein sizes reported in the literature [ 291 , 304 , 305 ]. Here, the target protein sHER2 was added in saturation (200 nM) to ensure full nanoprobe coverage [ 291 ].…”

Section: Optical Detection Methodssupporting

confidence: 91%

Homogeneous Biosensing Based on Magnetic Particle Labels

Schrittwieser

Pelaz

Parak

et al. 2016

Sensors

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The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation.

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“…30 Thus, after image processing, it is currently possible to give accurate results about the shape and size of biological complexes, in close agreement with other biophysical methodologies as dynamic light scattering. 31 Purified SOS1 was analyzed with a transmission electron microscope after being adsorbed to glow-discharged carbon coated grids and stained with 2% uranyl formate. Grids were observed using a JEOL JEM-2100 transmission electron microscope operated at 200 kV and a nominal magnification of 20,000.…”

Section: Electron Microscopy and 3d Reconstructionsmentioning

confidence: 99%

Structural Insights on the Plant Salt-Overly-Sensitive 1 (SOS1) Na+/H+ Antiporter

Núñez-Ramírez

Sánchez-Barrena

Villalta

et al. 2012

Journal of Molecular Biology

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Highlights The plant Na + /H + antiporter SOS1 is critical for salt tolerance. SOS1 is a homodimer folded into a transmembrane and a cytosolic domain. The regulatory mechanism is based on the concerted rearrangement of these domains  The SOS1 structure provides a model valuable for biotechnological applications. Keywords: electron microscopy; membrane protein; plant salt tolerance; protein structure; Na + transport. SummaryThe Arabidopsis thaliana Na + /H + antiporter SOS1 is essential to maintain low intracellular levels of toxic Na + under salt stress. Available data show that the plant SOS2 protein kinase and its interacting activator, the SOS3 calcium-binding protein, function together in decoding calcium signals elicited by salt stress and regulating the phosphorylation state and the activity of SOS1. *Manuscript Click here to view linked References 2Molecular genetic studies have shown that the activation implies a domain reorganization of the antiporter cytosolic moiety indicating that there is a clear relationship between function and molecular structure of the antiporter. To provide information on this issue, we have carried out in vivo and in vitro studies on the oligomerization state of SOS1. In addition, we have performed electron microscopy and single particle reconstruction of negatively stained full length and active SOS1. Our studies show that the protein is a homodimer that contains a membrane domain similar to that found in other antiporters of the family, and an elongated, large and structured cytosolic domain.Both the transmembrane and cytosolic moieties contribute to the dimerization of the antiporter. The close contacts between the transmembrane and the cytosolic domains provide a link between regulation and transport activity of the antiporter.

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Size and conformational features of ErbB2 and ErbB3 receptors: a TEM and DLS comparative study

Cited by 12 publications

References 30 publications

Homogeneous Protein Analysis by Magnetic Core–Shell Nanorod Probes

Homogeneous Protein Analysis by Magnetic Core–Shell Nanorod Probes

Homogeneous Biosensing Based on Magnetic Particle Labels

Structural Insights on the Plant Salt-Overly-Sensitive 1 (SOS1) Na+/H+ Antiporter

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