1
|
Araiza-Olivera D, Gutierrez-Aguilar M, Espinosa-García AM, García-García JA, Tapia-Orozco N, Sánchez-Pérez C, Palacios-Reyes C, Escárcega D, Villalón-López DN, García-Arrazola R. From bench to bedside: Biosensing strategies to evaluate endocrine disrupting compounds based on epigenetic events and their potential use in medicine. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2020; 80:103450. [PMID: 32622887 DOI: 10.1016/j.etap.2020.103450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 06/12/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
The relationship between endocrine system disorders and health risks due to chemical environmental compounds has become a growing concern in recent years. Involuntary exposure to endocrine disruptors (EDCs) is associated with the worldwide increase of diseases such as cancer, obesity, diabetes, and neurocortical disorders. EDCs are compounds that target the nuclear hormonereceptors (NHR) leading to epigenetic changes. Consequently, the use of biosensing strategies based on epigenetic events have a great potential to provide outstanding information about the exposition of EDCs and their evaluation in human health. This review addresses the novel trends in biosensing EDCs evaluation based on DNA methylation assays associated with different human diseases.
Collapse
Affiliation(s)
- D Araiza-Olivera
- Department of Chemistry and Biomolecules, Institute of Chemistry, UNAM, Mexico.
| | | | - A M Espinosa-García
- Unidad de Medicina Genómica, Hospital General de México, Dr. Balmis 148, Mexico City, Mexico.
| | - J A García-García
- Department of Education, Hospital General de México, Dr. Balmis 148, Mexico City, Mexico.
| | - N Tapia-Orozco
- Departmentof Food Science and Biotechnology, Faculty of Chemistry, Universidad Nacional Autónoma de México, Ave. Universidad 3000, 04510, Coyoacán, Mexico City, Mexico.
| | - C Sánchez-Pérez
- Institute of Applied Sciences and Technology, Faculty of Chemistry, Universidad Nacional Autónoma de México, Ave. Universidad 3000, 04510, Coyoacán, Mexico City, Mexico.
| | - C Palacios-Reyes
- Laboratory of Genetics and Molecular Diagnostics, Juarez Hospital of Mexico, Mexico City, Mexico.
| | - D Escárcega
- Instituto Tecnológico y de Estudios Superiores de Monterrey, Campus Ciudad de México, calle del Puente 222, Ejidos de Huipulco, Tlalpan 14380, Mexico City, Mexico.
| | - Demelza N Villalón-López
- Instituto Politénico Nacional-Escuela Nacional de Ciencias Biológicas, Departamento de Química Orgánica, Prolongación de Carpio y Plande Ayala, colonia Casco de Santo Tomás. Del, Miguel Hidalgo, 11350, Mexico.
| | - R García-Arrazola
- Departmentof Food Science and Biotechnology, Faculty of Chemistry, Universidad Nacional Autónoma de México, Ave. Universidad 3000, 04510, Coyoacán, Mexico City, Mexico.
| |
Collapse
|
2
|
Critical parameters in surface plasmon resonance biosensor development: The interaction between estrogen receptor and estrogen response element as model. Biochimie 2020; 171-172:12-20. [PMID: 32017967 DOI: 10.1016/j.biochi.2020.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 01/31/2020] [Indexed: 11/23/2022]
Abstract
Estrogenic compounds are contaminants that may be active at low concentrations and are a major concern for environmental quality. They interact with organisms via Estrogen Receptors (ER). Some detection methods which have been developed use the ability of ER to interact with short consensus DNA sequences known as Estrogen Response Elements (ERE). Surface Plasmon Resonance (SPR) based techniques allow detection of interaction without labelled molecule use. Such optical transductors are widely used to convert the biological recognition signals into electric quantifiable signals. In this study, SPR is used to assess signal variation in the presence of estrogenic compounds. The combination of physical properties and biological recognition events (e.g. ER/ERE) permits the development of biosensors. These require several steps: activation of the surface, DNA sequence binding, ERE sequence evaluation, ER preparation, characterization of binding properties and regeneration of the surface. This article focuses on the mode of surface activation, protein-DNA binding conditions and the regeneration of ERE. After giving a summary of the literature concerning the usual conditions employed in these steps, an evaluation of some key parameters is given.
Collapse
|
3
|
Aybeke EN, Ployon S, Brulé M, De Fonseca B, Bourillot E, Morzel M, Lesniewska E, Canon F. Nanoscale Mapping of the Physical Surface Properties of Human Buccal Cells and Changes Induced by Saliva. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:12647-12655. [PMID: 31448614 DOI: 10.1021/acs.langmuir.9b01979] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The mucosal pellicle, also called salivary pellicle, is a thin biological layer made of salivary and epithelial constituents, lining oral mucosae. It contributes to their protection against microbiological, chemical, or mechanical insults. Pellicle formation depends on the cells' surface properties, and in turn the pellicle deeply modifies such properties. It has been reported that the expression of the transmembrane mucin MUC1 in oral epithelial cells improves the formation of the mucosal pellicle. Here, we describe an approach combining classical and functionalized tip atomic force microscopy and scanning microwave microscopy to characterize how MUC1 induces changes in buccal cells' morphology, hydrophobicity, and electric properties to elucidate the physicochemical mechanisms involved in the enhancement of the anchoring of salivary proteins. We show that MUC1 expression did not modify drastically the morphology of the epithelial cells' surface. MUC1 expression, however, resulted in the presence of more hydrophobic and more charged areas at the cell surface. The presence of salivary proteins decreased the highest attractive and repulsive forces recorded between the cell surface and a functionalized hydrophobic atomic force microscopy (AFM) tip, suggesting that the most hydrophobic and charged areas participate in the binding of salivary proteins. The cells' dielectric properties were altered by both MUC1 expression and the presence of a mucosal pellicle. We finally show that in the absence of MUC1, the pellicle appeared as a distinct layer poorly interacting with the cells' surface. This integrative AFM/scanning microwave microscopy approach may usefully describe the surface properties of various cell types, with relevance to the bioadhesion or biomimetics fields.
Collapse
Affiliation(s)
- Ece Neslihan Aybeke
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université de Bourgogne Franche-Comté , Dijon F-21000 , France
| | - Sarah Ployon
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université de Bourgogne Franche-Comté , Dijon F-21000 , France
| | - Marine Brulé
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université de Bourgogne Franche-Comté , Dijon F-21000 , France
| | - Brice De Fonseca
- ICB UMR CNRS 6303, Université de Bourgogne Franche-Comté , Dijon F-21078 , France
| | - Eric Bourillot
- ICB UMR CNRS 6303, Université de Bourgogne Franche-Comté , Dijon F-21078 , France
| | - Martine Morzel
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université de Bourgogne Franche-Comté , Dijon F-21000 , France
| | - Eric Lesniewska
- ICB UMR CNRS 6303, Université de Bourgogne Franche-Comté , Dijon F-21078 , France
| | - Francis Canon
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université de Bourgogne Franche-Comté , Dijon F-21000 , France
| |
Collapse
|
4
|
Azzopardi CL, Chollet F, Manceau JF, Boireau W. Analyte capture in an array of functionalized droplets for a regenerable biosensor. BIOMICROFLUIDICS 2019; 13:054105. [PMID: 31592056 PMCID: PMC6768797 DOI: 10.1063/1.5115494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 09/17/2019] [Indexed: 06/10/2023]
Abstract
We describe in this work an advanced microfluidic chip for the capture of bioanalyte on the surface of droplets arranged in a dense array. We show the procedure for generating, functionalizing, and arranging the droplets inside the device for capturing a specific bioanalyte. Then, we demonstrate the capacity of the array to capture analyte from a cross-flowing liquid, using a biotin/streptavidin model. The paper also proposes to use the droplets array, after integration with acoustic detection, as a regenerable detection interface for bioanalyte sensing. We model the arrangement of droplet in dense array and show that they present a larger effective capture surface and shorter capture distance than standard flat surface biosensor of the same footprint. As the droplets can be easily evacuated and replaced inside the device analysis chamber, the proposed biosensor would allow biointerface regeneration and chain measurement without dismounting the device.
Collapse
Affiliation(s)
- C-L Azzopardi
- FEMTO-ST Institute, Univ. Bourgogne Franche-Comté CNRS, 15B av. des Montboucons, 25030 Besançon cedex, France
| | - F Chollet
- FEMTO-ST Institute, Univ. Bourgogne Franche-Comté CNRS, 15B av. des Montboucons, 25030 Besançon cedex, France
| | - J-F Manceau
- FEMTO-ST Institute, Univ. Bourgogne Franche-Comté CNRS, 15B av. des Montboucons, 25030 Besançon cedex, France
| | - W Boireau
- FEMTO-ST Institute, Univ. Bourgogne Franche-Comté CNRS, 15B av. des Montboucons, 25030 Besançon cedex, France
| |
Collapse
|
5
|
Pellequer JL, Parot P, Navajas D, Kumar S, Svetličić V, Scheuring S, Hu J, Li B, Engler A, Sousa S, Lekka M, Szymoński M, Schillers H, Odorico M, Lafont F, Janel S, Rico F. Fifteen years of Servitude et Grandeur
to the application of a biophysical technique in medicine: The tale of AFMBioMed. J Mol Recognit 2018; 32:e2773. [DOI: 10.1002/jmr.2773] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
| | | | - Daniel Navajas
- Institute for Bioengineering of Catalonia and CIBER de Enfermedades Respiratorias; Universitat de Barcelona; Barcelona Spain
| | - Sanjay Kumar
- Departments of Bioengineering and Chemical & Biomolecular Engineering; University of California, Berkeley; Berkeley California USA
| | | | - Simon Scheuring
- Department of Anesthesiology, Department of Physiology and Biophysics; Weill Cornell Medicine; New York City New York USA
| | - Jun Hu
- Shanghai Advanced Research Institute; Chinese Academy of Sciences; Shanghai China
- Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai China
| | - Bin Li
- Shanghai Advanced Research Institute; Chinese Academy of Sciences; Shanghai China
- Shanghai Institute of Applied Physics; Chinese Academy of Sciences; Shanghai China
| | - Adam Engler
- Department of Bioengineering; University of California San Diego; La Jolla California USA
| | - Susana Sousa
- i3S-Instituto de Investigação e Inovação em Saúde; Universidade do Porto; Porto Portugal
- INEB-Instituto de Engenharia Biomédica; Universidade do Porto; Porto Portugal
- ISEP-Instituto Superior de Engenharia; Politécnico do Porto; Portugal
| | - Małgorzata Lekka
- Institute of Nuclear Physics Polish Academy of Sciences; Kraków Poland
| | - Marek Szymoński
- Center for Nanometer-scale Science and Advanced Materials, NANOSAM, Faculty of Physics, Astronomy and Applied Computer Science; Jagiellonian University; Kraków Poland
| | | | - Michael Odorico
- Institut de Chimie Séparative de Marcoule (ICSM), CEA, CNRS, ENSCM, Univ Montpellier, Marcoule; Montpellier France
| | - Frank Lafont
- Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U1019, CHU Lille, Institut Pasteur de Lille, Univ Lille; Lille France
| | - Sebastien Janel
- Center for Infection and Immunity of Lille, CNRS UMR 8204, INSERM U1019, CHU Lille, Institut Pasteur de Lille, Univ Lille; Lille France
| | - Felix Rico
- LAI, U1067, Aix-Marseille Univ, CNRS, INSERM; Marseille France
| |
Collapse
|
6
|
Exploring Protein⁻Protein Interaction in the Study of Hormone-Dependent Cancers. Int J Mol Sci 2018; 19:ijms19103173. [PMID: 30326622 PMCID: PMC6213999 DOI: 10.3390/ijms19103173] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/09/2018] [Accepted: 10/10/2018] [Indexed: 12/20/2022] Open
Abstract
Estrogen receptors promote target gene transcription when they form a dimer, in which two identical (homodimer) or different (heterodimer) proteins are bound to each other. In hormone-dependent cancers, hormone receptor dimerization plays pivotal roles, not only in the pathogenesis or development of the tumors, but also in the development of therapeutic resistance. Protein–protein interactions (PPIs), including dimerization and complex formation, have been also well-known to be required for proteins to exert their functions. The methods which could detect PPIs are genetic engineering (i.e., resonance energy transfer) and/or antibody technology (i.e., co-immunoprecipitation) using cultured cells. In addition, visualization of the target proteins in tissues can be performed using antigen–antibody reactions, as in immunohistochemistry. Furthermore, development of microscopic techniques (i.e., electron microscopy and confocal laser microscopy) has made it possible to visualize intracellular and/or intranuclear organelles. We have recently reported the visualization of estrogen receptor dimers in breast cancer tissues by using the in situ proximity ligation assay (PLA). PLA was developed along the lines of antibody technology development, and this assay has made it possible to visualize PPIs in archival tissue specimens. Localization of PPI in organelles has also become possible using super-resolution microscopes exceeding the resolution limit of conventional microscopes. Therefore, in this review, we summarize the methodologies used for studying PPIs in both cells and tissues, and review the recently reported studies on PPIs of hormones.
Collapse
|
7
|
Leclercq G, Laïos I, Elie-Caille C, Leiber D, Laurent G, Lesniewska E, Tanfin Z, Jacquot Y. ERα dimerization: a key factor for the weak estrogenic activity of an ERα modulator unable to compete with estradiol in binding assays. J Recept Signal Transduct Res 2016; 37:149-166. [PMID: 27400858 DOI: 10.1080/10799893.2016.1203940] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Estrothiazine (ESTZ) is a weak estrogen sharing structural similarities with coumestrol. ESTZ failed to compete with [3H]17β-estradiol ([3H]17β-E2) for binding to the estrogen receptor α (ERα), questioning its ability to interact with the receptor. However, detection by atomic force spectroscopy (AFS) of an ESTZ-induced ERα dimerization has eliminated any remaining doubts. The effect of the compound on the proliferation of ERα-positive and negative breast cancer cells confirmed the requirement of the receptor. The efficiency of ESTZ in MCF-7 cells was weak without any potency to modify the proliferation profile of estradiol and coumestrol. Growth enhancement was associated with a proteasomal degradation of ERα without substantial recruitment of LxxLL coactivators. This may be related to an unusual delay between the acquisition by the receptor of an ERE-binding capacity and the subsequent estrogen-dependent transcription. A complementary ability to enhance TPA-induced AP-1 transcription was observed, even at concentrations insufficient to activate the ERα, suggesting a partly independent mechanism. ESTZ also rapidly and transiently activated ERK1/2 likely through membrane estrogenic pathways provoking a reorganization of the actin network. Finally, the systematic absence of biological responses with an ESTZ derivative unable to induce ERα dimerization stresses the importance of this step in the action of the compound, as reported for conventional estrogens. In view of the existence of many other ERα modulators (endocrine disruptors such as, for example, pesticides, environmental contaminants or phytoestrogens) with extremely weak or similar apparent lack of binding ability, our work may appear as pilot investigation for assessing their mechanism of action.
Collapse
Affiliation(s)
- Guy Leclercq
- a Laboratoire J.-C. Heuson de Cancérologie Mammaire , Université Libre de Bruxelles (U.L.B.), Institut Jules Bordet , Brussels , Belgium
| | - Ioanna Laïos
- a Laboratoire J.-C. Heuson de Cancérologie Mammaire , Université Libre de Bruxelles (U.L.B.), Institut Jules Bordet , Brussels , Belgium
| | - Céline Elie-Caille
- b Institut FEMTO-ST, CNRS UMR 6174, Université de Bourgogne Franche-Comté , Besançon , France
| | - Denis Leiber
- c Laboratoire Signalisation et Régulations Cellulaires , Institut de Biochimie et de Biologie Moléculaire et Cellulaire, CNRS UMR 8619, Université Paris-Sud , Orsay Cedex , France.,d INSERM U1063, Stress Oxydant et Pathologies Métaboliques, Université d'Angers , Angers , France
| | - Guy Laurent
- e Service d'Histologie et de Cytologie Expérimentale, Faculté de Médecine et de Pharmacie , Université de Mons-Hainaut , Mons , Belgium
| | - Eric Lesniewska
- f ICB, CNRS UMR 6303, Université de Bourgogne Franche-Comté , Dijon , France
| | - Zahra Tanfin
- c Laboratoire Signalisation et Régulations Cellulaires , Institut de Biochimie et de Biologie Moléculaire et Cellulaire, CNRS UMR 8619, Université Paris-Sud , Orsay Cedex , France
| | - Yves Jacquot
- g Département de Chimie, CNRS UMR 7203 LBM , Sorbonne Universités - UPMC Univ Paris 06, Ecole Normale Supérieure, PSL Research University , Paris , France
| |
Collapse
|
8
|
Habauzit D, Bayle S, Benimelis D, Chopineau J, Roig B. Impact of biochemical design on estrogen receptor/estrogen response element interaction by surface plasmon resonance technology. Arch Biochem Biophys 2014; 541:61-6. [DOI: 10.1016/j.abb.2013.11.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 10/23/2013] [Accepted: 11/17/2013] [Indexed: 01/27/2023]
|
9
|
Li Y, Qiao H, Yan W, Zhang J, Xing C, Wang H, Zhang B, Tang J. Molecular recognition force spectroscopy study of the dynamic interaction between aptamer GBI-10 and extracellular matrix protein tenascin-C on human glioblastoma cell. J Mol Recognit 2013; 26:46-50. [PMID: 23280617 DOI: 10.1002/jmr.2242] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Revised: 09/04/2012] [Accepted: 09/16/2012] [Indexed: 11/09/2022]
Abstract
Molecular recognition force spectroscopy (MR-FS) was applied to investigate the dynamic interaction between aptamer GBI-10 and tenascin-C (TN-C) on human glioblastoma cell surface at single-molecule level. The unbinding force between aptamer GBI-10 and TN-C was 39 pN at the loading rate of 0.3 nN sec⁻¹. A series of kinetic parameters concerning interaction process such as the unbinding force f(u) , the association rate constant k(on) , dissociation rate constant at zero force k(off) , and dissociation constant K(D) for aptamer GBI-10/TN-C complexes were acquired. In addition, the interaction of aptamer GBI-10 with TN-C depended on the presence of Mg²⁺. This work demonstrates that MR-FS can be used as an attractive tool for exploring the interaction forces and dynamic process of aptamer and ligand at the single-molecule level. As a future perspective, MR-FS may be used as a potential diagnostic and therapeutic tool by combining with other techniques.
Collapse
Affiliation(s)
- Yongjun Li
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Kerdivel G, Habauzit D, Pakdel F. Assessment and molecular actions of endocrine-disrupting chemicals that interfere with estrogen receptor pathways. Int J Endocrinol 2013; 2013:501851. [PMID: 23737774 PMCID: PMC3659515 DOI: 10.1155/2013/501851] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 03/26/2013] [Accepted: 03/28/2013] [Indexed: 01/11/2023] Open
Abstract
In all vertebrate species, estrogens play a crucial role in the development, growth, and function of reproductive and nonreproductive tissues. A large number of natural or synthetic chemicals present in the environment and diet can interfere with estrogen signaling; these chemicals are called endocrine disrupting chemicals (EDCs) or xenoestrogens. Some of these compounds have been shown to induce adverse effects on human and animal health, and some compounds are suspected to contribute to diverse disease development. Because xenoestrogens have varying sources and structures and could act in additive or synergistic effects when combined, they have multiple mechanisms of action. Consequently, an important panel of in vivo and in vitro bioassays and chemical analytical tools was used to screen, evaluate, and characterize the potential impacts of these compounds on humans and animals. In this paper, we discuss different molecular actions of some of the major xenoestrogens found in food or the environment, and we summarize the current models used to evaluate environmental estrogens.
Collapse
Affiliation(s)
- Gwenneg Kerdivel
- Institut de Recherche en Santé Environnement Travail (IRSET), INSERM U1085, TREC Team, SFR Biosit, University of Rennes 1, 35042 Rennes Cedex, France
| | - Denis Habauzit
- Institut de Recherche en Santé Environnement Travail (IRSET), INSERM U1085, TREC Team, SFR Biosit, University of Rennes 1, 35042 Rennes Cedex, France
| | - Farzad Pakdel
- Institut de Recherche en Santé Environnement Travail (IRSET), INSERM U1085, TREC Team, SFR Biosit, University of Rennes 1, 35042 Rennes Cedex, France
| |
Collapse
|
11
|
Immuno-MALDI-MS in human plasma and on-chip biomarker characterizations at the femtomole level. SENSORS 2012. [PMID: 23202203 PMCID: PMC3522956 DOI: 10.3390/s121115119] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Immuno-SPR-MS is the combination of immuno-sensors in biochip format with mass spectrometry. This association of instrumentation allows the detection and the quantification of proteins of interest by SPR and their molecular characterization by additional MS analysis. However, two major bottlenecks must be overcome for a wide diffusion of the SPR-MS analytical platform: (i) To warrant all the potentialities of MS, an enzymatic digestion step must be developed taking into account the spot formats on the biochip and (ii) the biological relevancy of such an analytical solution requires that biosensing must be performed in complex media. In this study, we developed a procedure for the detection and the characterization at ∼1 μg/mL of the LAG3 protein spiked in human plasma. The analytical performances of this new method was established, particularly its specificity (S/N > 9) and sensitivity (100% of LAG3 identification with high significant mascot score >68 at the femtomole level). The collective and automated on-chip MALDI-MS imaging and analysis based on peptidic fragments opens numerous applications in the fields of proteomics and diagnosis.
Collapse
|
12
|
Celik E, Moy VT. Nonspecific interactions in AFM force spectroscopy measurements. J Mol Recognit 2012; 25:53-6. [PMID: 22213450 DOI: 10.1002/jmr.2152] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sample-probe contact duration (dwell time) and loading force are two important parameters for the atomic force microscopy (AFM) force spectroscopy measurements of ligand-receptor interaction. A prolonged contact time may be required to initiate ligand-receptor binding as a result of slow on-rate kinetics or low reactant density. In general, increasing contact duration promotes nonspecific interactions between the substrate and the functionalized cantilever and, thus, masking the detection of the specific interactions. To reduce the nonspecific interactions in AFM force measurements requiring extended substrate-probe contact, we investigated the interaction of bovine serum albumin (BSA)-functionalized cantilever with BSA-coated glass, polyethylene glycol (PEG)-functionalized glass, Pluronic-treated Petri dishes and agarose beads. The frequency of nonspecific interaction between the BSA-functionalized cantilever and the different samples increased with loading force and dwell time. This increase in nonspecific adhesion can be attributed to the interaction mediated by forced unfolding of BSA. By reducing the loading force, the contact duration of the AFM probe with an agarose bead can be extended to a few minutes without nonspecific adhesion.
Collapse
Affiliation(s)
- Emrah Celik
- Department of Physiology and Biophysics, University of Miami School of Medicine, Miami, FL 33136, USA.
| | | |
Collapse
|