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Molecular interactions observed in a real time. – possibilities and limitations of SPR technology. Bogdan Walkowiak Department of Biophysics Technical University of Lodz and Department of Molecular and Medical Biophysics, Medical University of Lodz. Endpoint assay.
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Molecular interactions observed in a real time – possibilities and limitations of SPR technology Bogdan Walkowiak Department of Biophysics Technical University of Lodz and Department of Molecular and Medical Biophysics, Medical University of Lodz
SPR – Surface Plasmon Resonanse kx=2Pn1sin(q)/l ksp=(ng2n22/ng2+n22)0.5
SPR Detection System Optical detectionunit Light source I I II II Polarizedlight Reflected light Prism II Sensor chip withgold film I Sensorgram Flow channel
Microfluidic system IFC Liquid Handling
Gold-Dextran Surfaces Specific layer Dextran layer • Biocompatible • Low non-specificbinding • More than 100 runs on the same surface Linker layer Gold film Glass
The Sensorgram Resonance Signal (KRU) 18 Dissociation 16 Kinetics Regeneration 14 Association Concentration 12 100 200 300 400 500 600 Time (s)
Correlation between SPR response and surface concentration Signal proportional to massSame specific response for different proteins
Protein concentration at the sensor surface pH 2.8 pH 4.0 pH 6.8
Protein immobilization at the sensor surface saturation concentration and immobilization activation
Recombinant protein mediating fibrynolyitc process Szemraj J., Pietrucha T., Nowak P., Walkowiak B. In preparation 2002
pH-dependence of MBP and DNAK interaction Selmaj K., Ćwiklińska H., Walkowiak B. In preparation 2002
Final presentation of pH-dependence for MBP and DNAK Selmaj K., Ćwiklińska H., Walkowiak B. In preparation 2002
Specific antibody binding to immobilized MBP protein Selmaj K., Ćwiklińska H., Walkowiak B. In preparation 2002
Specific binding inhibition by Mab against MBP protein Selmaj K., Ćwiklińska H., Walkowiak B. In preparation 2002
Acid glycoprotein binding to immobilized PAI-1 Boncela J., Papiweska I., Fijałkowska I., Walkowiak B., Cierniewski CS. J..Biol.Chem,276, 35305, 2001
Vitronectin binding to immobilized PAI-1 Boncela J., Papiweska I., Fijałkowska I., Walkowiak B., Cierniewski CS. J..Biol.Chem,276, 35305, 2001
Preparation of sensor surface for NCD-plasma proteins interaction Glass plate one side covered with gold film Carbon deposition by RF CVPD technology Walkowiak B et.al. J. Wide Bandgap Materials, June 2002
Raman spectrometry analysis of prepared sensor surface Walkowiak B et.al. J. Wide Bandgap Materials, June 2002
Adsorbtion of plasma proteins to the NCD surface Walkowiak B et.al. J. Wide Bandgap Materials, June 2002
Sensor for detection of platelet adhesion to immobilized fibrinogen Immobilization of rabbit anti-fibrinogen at the sensor surface Walkowiak B et.al. J. Wide Bandgap Materials, June 2002
Adhesion of blood platelets to the sensor with immobilized fibrinogen fibrinogen suspension of blood platelets regeneration adhered platelets bound fibrinogen Walkowiak B et.al. J. Wide Bandgap Materials, June 2002
Effect of high salt concentration on antibody-ligand interaction
Effect of high salt concentration on antibody-ligand interaction
Sample Recovery and Fractionation Fractionate dissociating analyte for - re-injection - sequencing - mass spectrometry - electrophoresis - PCR Recover excess sample during injection - save expensive sample and reagents Recover eluted material for - enzymatic transfer assays - on-surface cleavage processes - alterations due to binding or regeneration 563
Limitations Molecular weight of analyte not less than 200 Limitet chemical resistivity to organic solvents Residual interaction of analyte with dextran matrix Active for measuremet distance from a sensor surface is limited to 300 nm
Thank you very much for your attention