Small molecular drugs
SPR is a powerful and sensitive tool for direct measurement of small molecules due to its pure kinetic properties of high quality kinetics.
SPR for small molecular interaction
As a sensitive platform, SPR can determine the drug-target interaction, which is also suitable for small molecules. Label-free interactions are measured in real-time revealing affinity and kinetic of the binding. Optimize various analytes (Nucleotide, Peptide, Drug molecule, Antibody, Virus etc.) targeting to different ligands (Protein, Nucleotide, Peptide, Receptor, Membrane receptor, Antibody etc.). Interaction measurements can be performed in diverse liquids, including complex liquids such as serum, saliva or organic solvents.
There are five reasons for choosing SPR to measure small molecules:
1. Direct measurement of small molecules
2. High quality data can be obtained by dynamics
3. Low cost
4. Easy shift from targeting to internalization studies
5. Answers to new challenges in biopharmaceutical development and manufacturing
There are four key questions about small molecules that SPR can answer:
1. What is small molecule weight drug affinity to protein ?
2. How fast is molecule X association and dissociation kinetics to molecule Y?
3. Which drug molecule is best to bind receptor ?
4. What is the release rate of drug from material?
Application of DNA quantitative detection
DNA assays can be applied for detecting genetic material in order to detect genetic disorders, mutations, gene transfection or species from a large variety of samples. By assaying specific single stranded oligonucleotides of over 20 nucleotides in length, it is possible to detect and quantify unique gene sequences from large amounts of genetic material.The 27 unit Oligonuclear is self adsorbed on a standard gold sensing surface. A (2-hydroxyethyl)-aliphatic amide molecule was used to adsorb nonspecific binding on the surface. Single stranded dNA samples with complementary sequences were detected, and non complementary dNA of the same lens and bovine serum albumin (BSA) was tested. Sensby SPR showed good performance in a wide concentration range (0.1nm to 10μm), and non complementary dNA and 1000nm BSA had no signal response.
Application of drug cell interaction
In vitro cell detection is widely used in drug development. Generally speaking, the materials that need to be labeled are based on UV, fluorescence or mass spectrometry. The multiparameter SPR can measure the interaction in real time without labeling under a constant and controlled flow condition. SPR measures a wide angle range and the entire SPR curve, and several parameters can be observed. The monolayer of madin-darby canine kidney (MDCKII) cells were deposited on the gold sensor slide. The interaction of propranolol and D-Mannitol with monolayer cells was successfully determined. After stimulation, some propranolol remained in the cell layer, while D-Mannitol was removed. Through the measurement of SPR, we can even distinguish the quasi cellular and extracellular drug absorption pathways.
Measurement of small molecular weight drug protein interaction by SPR
The interaction of a small molecular weight drug to Human serum albumin (HSA) was measured with SPR. HSA was attached to a sensor surface with amine coupling chemistry. Affinity (KD) and kinetic constants (ka and kd) of interaction were determined with SPR. The volume effect is separated from the binding kinetics by kinetics, which ensures the high quality kinetic data.
