Microchip Electrophoresis Assay for Calmodulin Binding Proteins

Area of Science:

• Biochemistry
• Analytical Chemistry
• Molecular Biology

Background:

• Calmodulin is a crucial calcium signaling protein regulating diverse intracellular functions.
• Identifying calmodulin binding proteins is essential for understanding cellular processes.

Purpose of the Study:

• To develop a sensitive microchip assay for the separation and detection of calmodulin binding proteins.
• To optimize microchip electrophoresis and laser-induced fluorescence for this application.

Main Methods:

• Utilized a microchip electrophoresis platform with laser-induced fluorescence detection.
• Employed fluorescence-labeled calmodulin with a photoreactive diazirine crosslinker for selective protein detection.
• Compared microchip capillary zone electrophoresis, micellar electrokinetic chromatography/gel electrophoresis, and nanoparticle colloidal arrays.

Main Results:

• Successfully demonstrated *in vitro* crosslinking of calmodulin with calcineurin and nitric oxide synthase.
• Identified polydimethylsiloxane/glass chips with microchip zone electrophoresis as suboptimal for separation.
• Determined that sieving methods with suppressed electro-osmotic flow provided superior separation of calmodulin-protein conjugates.

Conclusions:

• The developed microchip assay offers a sensitive method for detecting calmodulin binding proteins.
• Optimized sieving-based microchip electrophoresis provides effective separation of calmodulin-protein photoproducts.