SPR Technology Research Articles

Rapid wavelength interval selection technology for multi-channel intensity-interrogation surface plasmon resonance imaging sensing

Intensity-interrogation surface plasmon resonance (I-SPR) provides the fastest imaging speed among various SPR techniques, including wavelength, phase, and angle-based detection. It also integrates easily with other devices and has substantial practical application potential. However, I-SPR's reliance on direct detection of reflected light intensity renders it sensitive to light source fluctuations and detector dark noise, and its dynamic range is relatively limited. To address these challenges, we have developed a multi-channel I-SPR sensing platform featuring rapid wavelength interval selection technology. This system optimizes the sensing wavelength according to the refractive indices of different samples, mitigating issues related to inconsistent SPR signals from various biomolecules. Our improved I-SPR technology enables high-throughput biomolecular detection with a refractive index range size of 2.035 × 10−2 for dynamic monitoring, reaching a leading role among the existing I-SPR technologies. This represents the widest linear dynamic range for I-SPR to date. Experimental results on protein binding kinetic constants KD are consistent with those obtained from commercially available instruments. We believe that this study is expected to accelerate the development of SPR technology toward broader biological applications.

Identification of chemical compounds of Schizonepeta tenuifolia Briq. and screening of neuraminidase inhibitors based on AUF-MS and SPR technology

Schizonepeta tenuifolia Briq., as a traditional Chinese medicine, has the effect of treating influenza. There have been few comprehensive studies on the holistic chemical composition of Schizonepeta tenuifolia and the active substances acting on neuraminidase (NA) to treat influenza. In present study, a synthetic identification method including GC-MS and UPLC-Q-Orbitrap-MS combined with GNPS (Global Natural Product Social Molecular Network) technology was established and applied to identify the chemical constituents of Schizonepeta tenuifolia Briq. A total of 134 compounds were identified, including 42 volatile components and 92 non-volatile components. The potential NA inhibitors of Schizonepeta tenuifolia were explored by an affinity ultrafiltration - mass spectrometry - surface plasmon resonance (AUF-MS-SPR) strategy. Eleven compounds were screened out by AUF-MS and their binding forces to NA were detected by SPR. Among them, 5 compounds with excellent binding ability were further tested the KD value. Meanwhile, the NA inhibitory activities of the 11 compounds were verified in vitro. In conclusion, a holistic material base was established to provide a reference for further development of Schizonepeta tenuifolia and an AUF-MS-SPR strategy based on binding ability was selected to screen substances of interest from complex systems.

The designation, synthesis, and affinity determination of affinity peptide for anthrax protective antigen.

Detection of anthrax protective antigen is an effective way to diagnose anthracnose, and it plays an important part in the treatment of anthracnose. Affinity peptides, as a miniature biological recognition element, can quickly and effectively detect anthrax protective antigens. Based on computer-aided design technology (CAD), we have herein developed an affinity peptide design strategy for the detection of anthrax protective antigens. Firstly, six high-value mutation sites were determined based on the molecular docking between the template peptide and the receptor, and then the multi-site mutation of amino acids was carried out in order to establish a virtual peptide library. The library was selected by using molecular dynamics simulation and the best designed affinity peptide (code: P24) was found. The theoretical affinity with P24 peptide has increased by 19.8% compared with template peptide. Finally, the affinity with P24 peptide was measured by SPR technology to reach the nanomole level, which verified the effectiveness of the design strategy. The newly designed affinity peptide is expected to be used in the diagnosis of anthracnose.

Portable immuno nano biosensor for multiple disease detection using 3D printed SPR technologies

The role of biosensors as point-of-care devices is well explored in recent years and their usage in the current market has been highly increased after the outbreak of the COVID pandemic. The point-of-care devices generally use sensing principles of electrochemical, immune fluorescence, microbial and electromagnetic. The sensor we developed uses the phenomenon of Surface Plasmon resonance with optic fiber technology which is a novel design to implement in point-of-care devices. With the latest innovations and improvements in 3D printing technologies the development and prototyping of these POC devices have been accelerated to the greatest potential. Here the entire device was prototyped using Creality Upgraded Ender 3 2021 model 3D printer where the 3D files were sliced in Ultimaker Cura software and printed with PLA filament by fused filament deposition modeling (FFDM). The device has a USB light and camera source on either side of the sensing chamber and a cassette with optic fiber coated with respective antibodies as a sensing platform. The device is connected to respective USB ports and introduced with the sample over a cassette and placed in the reaction chamber. The reaction occurs spontaneously which is captured by the webcam and recorded by the software. We tested the bare sensor with increased concentrations of glycerol after coating it with a silver mirror by a standard reproducible method of Tollens silver mirror. The sensor showed the best sensitivity with increasing concentrations of glycerol. The sensor also immobilized with target antibodies of pLDH parasite lactate dehydrogenase by non-specific binders just by adding target bio-analyte and receptor over silver mirror functionalized surface and tested with positive control antigen of malaria parasite antigen. The sensor showed the highest sensitivity at 50X concentration of antigen and least at 10x concentration stating maximum and minimum values for a limit of detection. This device using this principle could has wide functionalities to detect multiple biological samples by changing the antibodies to our respective analyte over the reaction chip for multiple times with low cost.

Recent Advances in Surface Plasmon Resonance Microscopy

Surface plasmon resonance microscopy (SPRM) is a versatile technique for biosensing and imaging that facilitates high-sensitivity, label-free, real-time characterization. To date, SPR technology has been successfully commercialized and its performance has continued to improve. However, this method is inhibited by low spatial resolution and the inability to achieve single-molecule detection. In this report, we present an overview of SPRM research progress in the field of plasma imaging and sensing. A brief review of the technological advances in SPRM is outlined, as well as research progress in important applications. The combination of various new techniques with SPRM is emphasized. Finally, the current challenges and outlook of this technique are discussed.

Cardiac biomarkers and detection methods for myocardial infarction.

BackgroundA significant heart attack known as a myocardial infarction (MI) occurs when the blood supply to the heart is suddenly interrupted, harming the heart muscles due to a lack of oxygen. The incidence of myocardial infarction is increasing worldwide. A relationship between COVID-19 and myocardial infarction due to the recent COVID-19 pandemic has also been revealed.ObjectiveWe propose a biomarker and a method that can be used for the diagnosis of myocardial infarction, and an aptamer-based approach.ResultsFor the diagnosis of myocardial infarction, an algorithm-based diagnosis method was developed using electrocardiogram data. A diagnosis method through biomarker detection was then developed.ConclusionMyocardial infarction is a disease that is difficult to diagnose based on the aspect of a single factor. For this reason, it is necessary to use a combination of various methods to diagnose myocardial infarction quickly and accurately. In addition, new materials such as aptamers must be grafted and integrated into new ways.Purpose of ReviewThe incidence of myocardial infarction is increasing worldwide, and some studies are being conducted on the association between COVID-19 and myocardial infarction. The key to properly treating myocardial infarction is early detection, thus we aim to do this by offering both tools and techniques as well as the most recent diagnostic techniques.Recent FindingsMyocardial infarction is diagnosed using an electrocardiogram and echocardiogram, which utilize cardiac signals. It is required to identify biomarkers of myocardial infarction and use biomarker-based ELISA, SPR, gold nanoparticle, and aptamer technologies in order to correctly diagnose myocardial infarction.

Development of a portable multiplexed instrument for multi-proteins detection in human urine using surface plasmon resonance

Ideal urine screening should realize the detection of a variety of different urine proteins, corresponding to the diagnosis of different diseases. However, there is a lack of effective instruments to realize the simultaneous screening of albumin and light chain protein. In this paper, a specialized multiplexed urine protein detection instrument based on SPR technology was developed for quantitative detection of human serum albumin (HSA), beta-2-microglobulin (B2M), kappa light chain and lambda light chain protein. A modified BSA sensor membrane was developed to realize one-step direct detection of the analyte. The sensitivity, repeatability and specificity of the SPR instrument were analyzed and tested, and the standard curves of four proteins were calculated. Comparing the results between healthy people and nephrotic patients by our instrument, it was found that there was a significant difference in the two groups for HSA and B2M detection (p < 0.01), indicating that HSA and B2M are suitable markers for nephropathy diagnosis. Furthermore, the performance of our instrument was compared with commercialized platforms and got lower experimental concentrations than the immunoturbidimetry method in kappa and lambda detection. It will promote early screening of kidney and tumour diseases simultaneously by applying our SPR sensor in the future.

Research on Vector Bending SPR Sensor Based on V-Groove Fiber

Bending curvature measurement and bending direction identification are very important in the field of mechanical engineering. This study aimed to realize the high sensitivity direction recognition and curvature sensing based on SPR mechanism by a V-groove fiber SPR vector bending sensor. By CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> laser, multiple evenly spaced V-grooves were fabricated on the step multimode fiber. The V-groove fiber coupled the core mode to the cladding mode. By rotatably coating 50nm gold film on the cladding behind the V-groove area, and splicing with a multimode fiber with larger diameter to receive the light with SPR signal, the fiber SPR sensor was realized. When the sensing probe was concave inward, the V-groove was squeezed, the angle became smaller, and the excited cladding mode changed with it, resulting in the increase of SPR incident angle, the resonance valley blue shifted, and the sensitivity of curvature sensing wavelength is −5.98nm/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> . Similarly, when the sensing probe was convex outward, the angle became larger, resulting in the decrease of SPR incident angle, the resonance valley red shifted, and the sensitivity of curvature sensing wavelength is 1.42nm/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> . The proposed V-groove fiber SPR sensor realized the bending curvature measurement and bending direction identification. The manufacturing method is simple and the sensitivity is high, which opens up a new way for application of the SPR technology in bending measurement.

Surface Plasmon Resonance Imaging (SPRi) and Photonic Integrated Circuits (PIC) for COVID-19 Severity Monitoring

Direct optical detection methods such as surface plasmon resonance imaging (SPRi) and photonic-integrated-circuits (PIC)-based biosensors provide a fast label-free detection of COVID-19 antibodies in real-time. Each technology, i.e., SPRi and PIC, has advantages and disadvantages in terms of throughput, miniaturization, multiplexing, system integration, and cost-effective mass production. However, both technologies share similarities in terms of sensing mechanism and both can be used as high-content diagnostics at or near to point of care, where the analyte is not just quantified but comprehensively characterized. This is significant because recent results suggest that not only the antibody concentration of the three isotypes IgM, IgG, and IgA but also the strength of binding (affinity) gives an indication of potential COVID-19 severity. COVID-19 patients with high titers of low affinity antibodies are associated with disease severity. In this perspective, we provide some insights into how SPR and PIC technologies can be effectively combined and complementarily used for a comprehensive COVID-19 severity monitoring. This opens a route toward an immediate therapy decision to provide patients a treatment in an early stage of the infection, which could drastically lowers the risk of a severe disease course.

Spiral Structured Photonic Crystal Fiber-Based Plasmonic Sensor with Bimetallic Coating

We present a bimetallic coated, low-loss spiral lattice PCF sensor combined with SPR technology that achieves a high sensitivity. The sensing performance and properties of our recommended sensor are realized numerically by the Finite Element Method. Gold is utilized as the plasmonic layer and titanium Oxide (TiO2), which is sandwiched between the silica glass fiber and the gold coating, forming the bimetallic surface. As TiO2 has a high refractive index, they create a strong surface plasmon wave in the plasmonic region that attracts the evanescent field originating from the core region and increases the coupling effect plasmonic and core mode. Hence, the bimetallic coating is performed to achieve better sensing performance and strengthen the SPR process for the presented sensor. The presented sensor’s nominal tolerance is 12,000 nm/RIU for x-polarization to 11,000 MHz for y-polarization. The presented sensor is intended to be used in several applications and sensing fields due to its high sensitivity.

Substrate-induced modulation of protein-protein interactions within human mitochondrial cytochrome P450-dependent system

Steroidogenesis is strictly regulated at multiple levels, as produced steroid hormones are crucial to maintain physiological functions. Cytochrome P450 enzymes are key players in adrenal steroid hormone biosynthesis and function within short redox-chains in mitochondria and endoplasmic reticulum. However, mechanisms regulating supply of reducing equivalents in the mitochondrial CYP-dependent system are not fully understood. In the present work, we aimed to estimate how the specific steroids, substrates, intermediates and products of multistep reactions modulate protein-protein interactions between adrenodoxin (Adx) and mitochondrial CYP11 s. Using the SPR technology we determined that steroid substrates affect affinity and stability of CYP11s–Adx complexes in an isoform-specific mode. In particular, cholesterol induces a 4-fold increase in the rate of CYP11A1 – Adx complex formation without significant effect on dissociation (koff decreased ∼1.5-fold), overall increasing complex affinity. At the same time steroid substrates decrease the affinity of both CYP11B1 – Adx and CYP11B2 – Adx complexes, predominantly reducing their stability (4–7 fold). This finding reveals differentiation of protein-protein interactions within the mitochondrial pool of CYPs, which have the same electron donor. The regulation of electron supply by the substrates might affect the overall steroid hormones production. Our experimental data provide further insight into protein-protein interactions within CYP-dependent redox chains involved in steroidogenesis.

Screening and quantification of TNF-α ligand from Angelicae Pubescentis Radix by biosensor and UPLC-MS/MS

The aim of this study is to establish a method for rapid screening of active ingredients targeting TNF-α from Chinese herbal medicines. Take Angelicae Pubescentis Radix (APR) as an example, surface plasma resonance technique was used to establish for screening small molecule inhibitors of TNF-α from APR extract. Then UPLC-MS/MS coupled with chemometric was used for quantitative and evaluate the differences of the candidate compounds bound to TNF-α in APR from different sources. In the experiment, TNF-α protein was fixed on the CM5 chip surface of biacore T200 biosensor by amino coupling. A series of small molecular compounds in APR were screened and six phenolic acid compounds had a strong affinity for TNF-α protein and could be used as TNF-α antagonists. In summary, the targeted drug screening method for TNF-α protein based on SPR technology established in this study can be used to screen anti-TNF-α small molecule inhibitors. UPLC-MS/MS can accurately quantify 15 active ingredients, which provides reliable experimental data and new research ideas for targeted drug research on TNF-α protein.

Design, synthesis and identification of N, N-dibenzylcinnamamide (DBC) derivatives as novel ligands for α-synuclein fibrils by SPR evaluation system

PET imaging of α-synuclein (α-syn) deposition in the brain will be an effective tool for earlier diagnosis of Parkinson's disease (PD) due to α-syn aggregation is the widely accepted biomarker for PD. However, the necessary PET radiotracer for imaging is clinically unavailable until now. The lead compound discovery is the first key step for the study. Herein, we initially established an efficient biologically evaluation system well in highthroughput based on SPR technology, and identified a novel class of N, N-dibenzylcinnamamide (DBC) compounds as α-syn ligands through the assay. These compounds were proved to have high affinities against α-syn aggregates (KD < 10 nM), which well met the requirement of binding activity for the PET probe. These DBC compounds were firstly reported as α-syn ligands herein and the preliminary obtained structure has been further modified into F-labeled ones. Among them, a high-affinity tracer (5–41) with 1.03 nM (KD) has been acquired, indicating its potential as a new lead compound for developing PET radiotracer.

Electrografting of diazonium salt for SPR application

A general method to develop diazonium-based biochip for SPRi analysis is presented. The electrografting of carboxybenzene diazonium salt is optimized in order to fit with the requirement of the SPR technology. The influence of the surface preparation on plasmon quality is discussed and the performance of this original modified biochip is investigated for determining the binding constants between circulating ovalbumin and spotted anti-ovalbumin antibody. The kinetic constants are calculated and compared with literature and similar performances are reached confirming that diazonium based biochip is a good complement to commercial SPRi sensor.

Recent advances in surface plasmon resonance imaging: detection speed, sensitivity, and portability

Abstract Surface plasmon resonance (SPR) biosensor is a powerful tool for studying the kinetics of biomolecular interactions because they offer unique real-time and label-free measurement capabilities with high detection sensitivity. In the past two decades, SPR technology has been successfully commercialized and its performance has continuously been improved with lots of engineering efforts. In this review, we describe the recent advances in SPR technologies. The developments of SPR technologies focusing on detection speed, sensitivity, and portability are discussed in details. The incorporation of imaging techniques into SPR sensing is emphasized. In addition, our SPR imaging biosensors based on the scanning of wavelength by a solid-state tunable wavelength filter are highlighted. Finally, significant advances of the vast developments in nanotechnology-associated SPR sensing for sensitivity enhancements are also reviewed. It is hoped that this review will provide some insights for researchers who are interested in SPR sensing, and help them develop SPR sensors with better sensitivity and higher throughput.

Abstract 894: Discovery of YAP-TEAD protein-protein interaction (PPI) inhibitors for cancer therapy

Abstract The Hippo pathway is emerging as a critical player in several processes involved in cancer progression, including cell proliferation and EMT. YAP mediates the downstream effects of Hippo signaling, and high nuclear expression of YAP has been documented in many tumors types. YAP translocates to the nucleus, binds to TEAD transcription factor and drives the expression of growth factors, including CTGF, Cyr61 and surviving, suggesting that therapies targeting YAP-TEAD interaction are likely to have clinical impact for the treatment of cancer patients. However, due to the challenging nature of protein-protein interactions, a potent inhibitor that surpasses the affinity of the YAP-TEAD interactions has not been developed. All the critical residues for the YAP-TEAD interaction belong to interface S3. In order to identify interface S3 binders able to disrupt the YAP-TEAD interaction, we started a drug discovery program based on combined FBS/HTS strategy. TEAD protein drugabbility was assessed by fragment screen using NMR and SPR technologies. This approach, supported by assigned HSQC protein NMR information, provided fragment hits which were used as starting points for the identification of more potent binders. We also designed an AlphaLisa assay to validate the ability of our compounds to disrupt the YAP-TEAD interaction. 240,000 compounds of our proprietary library were screened using AlphaLisa assay. Several hits in the μM range were identified and further confirmed using SPR. Successful chemistry optimization generated compounds showing inhibitory activity in the AlphaLisa assay at 50-100 nM for the best compounds. To confirm the validity of our inhibitors, we constructed plasmids encoding TEAD protein fused to Gal4 DNA-binding domain. We transfected HEK293 cells with these plasmids together with Gal4-driven luciferase reporter plasmid in the presence of YAP S127A/S397A. Our compounds showed marked inhibition of cell-based transactivation assay at 3-10 μM. In order to establish a panel of cancer cell lines whose proliferation and target gene expression were either dependent or independent of YAP/TEAD, we selected several cell lines based on their mutational status, YAP nuclear localization, and their proliferative response to a siRNA targeting either YAP or TEAD. Our data show that YAP-TEAD inhibitors block both cell proliferation and target gene expression only in YAP/TEAD-dependent cell lines. In conclusion, we have successfully demonstrated that YAP-TEAD PPI can be inhibited by small molecules, and our compounds show activity in cell-based assays. Medicinal chemistry optimization on various series is ongoing to improve potency and DMPK parameters for further in vivo evaluation in cancer xenograft models. Citation Format: Anne Soude, Martine Barth, Stephanie Bocart, Frederic Thoreau, Philippe Masson, Isabelle Braccini, Christian Montalbetti, Pierre Broqua, Claudia Fromond. Discovery of YAP-TEAD protein-protein interaction (PPI) inhibitors for cancer therapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 894.

Abstract A129: Generation of YAP-TEAD Protein-Protein Interaction (PPI) inhibitors for the treatment of cancer

Abstract In the last few years the Hippo pathway has been recognized as a critical player in several processes involved in cancer progression, including cell proliferation, apoptosis and EMT. YAP and TAZ mediate the downstream effects of Hippo signaling, and high nuclear expression of YAP has been documented in many tumors including lung, colorectal, ovarian and skin cancers. When YAP translocates to the nucleus it binds to TEAD transcription factor and drives the expression of several growth factors, including CTGF, Cyr61 and survivin. This suggests that therapies targeting YAP-TEAD interaction are likely to have clinical impact for the treatment of cancer patients. However, due to the challenging nature of protein-protein interactions (PPIs), a potent inhibitor that surpasses the affinity of the YAP-TEAD interactions has not been developed. The YAP-TEAD complex has 3 interfaces, and all the critical residues for YAP-TEAD interaction belong to interface S3. In order to identify interface S3-TEAD binders able to disrupt the YAP-TEAD interaction, we started a drug discovery program based on a combined FBLD/HTS strategy. Drugabbility of TEAD protein was assessed by a fragment screen using NMR and SPR technologies. This approach, supported by assigned HSQC protein NMR information, provided fragment hits which were used as starting points for the identification of more potent binders. We also designed a dedicated AlphaScreen assay to validate the ability of our compounds to disrupt the YAP-TEAD interaction. Fifty thousand compounds of Inventiva's proprietary library were screened using the AlphaScreen assay. Several hits in the μM range were identified and further confirmed using SPR. Successful chemistry optimization based on the critical choice of starting Hit series during the Hit-to-Lead phase led us to generate compounds showing inhibitory activity in the AlphaScreen assay in the range of 50-100 nM for the best compounds. To further confirm the validity of our YAP-TEAD inhibitors, we constructed plasmids encoding TEAD protein fused to the Gal4 DNA-binding domain and transfected HEK293 cells with these plasmids together with a Gal4-driven luciferase reporter plasmid in the presence of YAP S127A. Our compounds showed a marked inhibition in the YAP-TEAD cell-based transactivation assay at concentrations ranging from 3-10 μM. In conclusion, we have successfully demonstrated that YAP-TEAD protein-protein interaction can be inhibited by small molecules, and that our compounds show activity in a cell-based assay. They are currently being evaluated for their ability to block cancer cell proliferation, and SAR on the various series is currently ongoing to improve potency and DMPK parameters for further in vivo evaluation in appropriate cancer xenograft models. Citation Format: Anne Soude, Martine Barth, Stephanie Bocart, Frederic Thoreau, Elina Mandry, Sylvie Contal, Philippe Masson, Isabelle Braccini, Christian Montalbetti, Pierre Broqua, Claudia Z-A Fromond. Generation of YAP-TEAD Protein-Protein Interaction (PPI) inhibitors for the treatment of cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A129.

Abstract 2200: A rational approach for discovery of inhibitors of YAP-TEAD interaction

Abstract The Hippo signalling pathway plays a major role in organ growth regulation and tumorigenesis. By sensing contact inhibition, the central kinase network of the hippo pathway controls nuclear translocation and activity of the YAP transcription factor. Once translocated in the nucleus, YAP interacts with the TEAD family of transcription factors and drives expression of gene involved in cell survival and proliferation. Deregulation of the hippo pathway frequently occurs in cancers and high nuclear expression of YAP has been documented in many tumors including lung, colorectal, ovarian and skin cancers. These data suggest that targeting the hippo pathway is a new therapeutic option for the treatment of a large number of cancers. Several approaches are currently proposed to target the hippo pathway such as inhibition of kinases and GPCRs that are upstream regulators of YAP nuclear translocation. However, because YAP and TEAD are the downstream effectors of the Hippo pathway, we believe that targeting YAP-TEAD interaction is the most promising approach to selectively counteract abnormal activity of the Hippo pathway. We have started a drug discovery program aimed at identifying potent inhibitors of YAP-TEAD interaction, based on a combined FBLD/HTS strategy. Druggability of the TEAD protein was assessed by a fragment screen using NMR and SPR technologies. This approach, conforted by assigned HSQC protein NMR information, provided fragment hits which are used as starting points for the identification of more potent binders. We have also designed a dedicated AlphaScreen assay to validate the ability of our compounds to disrupt the YAP-TEAD interaction. Fifty thousand compounds of the Inventiva's library were screened using the AlphaScreen. Several hits in the micromolar range were identified and further confirmed using SPR. Hits are currently tested for their ability to disrupt YAP-TEAD interaction in a cellular context with a transactivation assay and for their ability to block tumoral cell proliferation. Citation Format: Claudia Fromond, Laurent Chene, Anne Soude, Martine Barth, Christian Montalbetti, Pierre Broqua. A rational approach for discovery of inhibitors of YAP-TEAD interaction. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2200. doi:10.1158/1538-7445.AM2015-2200

Optical surface plasmon resonance biosensors in molecular fishing

An optical biosensor employing surface plasmon resonance is a highly efficient instrument applicable for direct real time registration of molecular interactions without additional use of any labels or coupled processes. As an independent approach it is especially effective in analysis of various ligand receptor interactions. SPR-biosensors are used for validation of studies on intermolecular interactions in complex biological systems (affinity profiling of various groups of proteins, etc.). Recently, potential application of the SPR-biosensor for molecular fishing (direct affinity binding of target molecules from complex biological mixtures on the optical biosensor surface followed by their elution for identification by LC-MS/MS) has been demonstrated. Using SPR-biosensors in such studies it is possible to solve the following tasks: (a) SPR-based selection of immobilization conditions required for the most effective affinity separation of a particular biological sample; (b) SPR-based molecular fishing for subsequent protein identification by mass spectrometry; (c) SPR-based validation of the interaction of identified proteins with immobilized ligand. This review considers practical application of the SPR technology in the context of recent studies performed in the Institute of Biomedical Chemistry on molecular fishing of real biological objects.

Rational targeting of subclasses of intermolecular interactions: elimination of nonspecific binding for analyte sensing.

The ability to target and control intermolecular interactions is crucial in the development of several different technologies. Here we offer a tool to rationally design liquid media systems that can modulate specific intermolecular interactions. This has broad implications in deciphering the nature of intermolecular forces in complex solutions and offers insight into the forces that govern both specific and nonspecific binding in a given system. Nonspecific binding still continues to be a problem when dealing with analyte detection across a range of different detection technologies. Here, we exemplify the problem of nonspecific binding on model membrane systems and when dealing with low-abundance protein detection on commercially available SPR technology. A range of different soluble reagents that target specific subclasses of intermolecular interactions have been tested and optimized to virtually eliminate nonspecific binding while leaving specific interactions unperturbed. Thiocyanate ions are used to target nonpolar interactions, and small reagents such as glycylglycylglycine are used to modulate the dielectric constant, which targets charge-charge and dipole interactions. We show that with rational design and careful modulation these reagents offer a step forward in dissecting the intermolecular forces that govern binding, alongside offering nonspecific binding elimination in detection systems.