N-Phenylnaphthalen-1-amine

Guide (The following is our recommended protocol. This protocol is only a guide and should be modified according to your specific needs).
Odorant Binding Protein (OBP) Binding Affinity Assay^[1]
1. Materials Preparation
Fluorescent probe: N-phenyl-1-naphthylamine, dissolved in methanol (MeOH) to prepare a 1 mM stock solution
Protein solution: 2 μM odorant binding protein (OBP), dissolved in 50 mM Tris-HCl buffer (pH 7.4)
Experimental temperature: 25 °C
Fluorescence spectrophotometer: equipped with a 1 cm quartz cuvette, excitation and emission slit widths set to 5 nm
Detection wavelengths: Excitation wavelength (λ_ex): 337 nm; Emission wavelength (λ_em): 407 nm
2. Fluorescence Binding Assay Procedure
2.1 Place 2 μM odorant binding protein solution into the cuvette.
2.2 Gradually add the N-phenyl-1-naphthylamine stock solution (1 mM in methanol), mixing gently after each addition.
2.3 Set the final concentration range to 1-20 μM.
2.4 After each addition, immediately record the fluorescence emission spectrum (range 380-460 nm).
2.5 Measure and record the emission intensity at 407 nm for plotting the binding curve.
3. Data Analysis
3.1 Plot fluorescence intensity against the concentration of free N-phenyl-1-naphthylamine.
3.2 Use a Scatchard plot for linearization and calculation of the binding constant.
3.3 Assume a 1:1 binding ratio and 100% protein activity.
2.4 The dissociation constant (K_d) of N-phenyl-1-naphthylamine with loc-OBP1 is 1.67 μM.
4. Competitive Binding Assay
4.1 Use a fixed concentration of 2 μM odorant binding protein and 1 μM N-phenyl-1-naphthylamine.
4.2 Add test ligands (dissolved in methanol) at final concentrations typically ranging from 1-20 μM.
4.3 Monitor the decrease in fluorescence intensity and plot the competitive binding curve.
4.4 Calculate the IC₅₀, and then convert it to the dissociation constant (K_d) of the test ligand.

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.