Protein quantification and visualization via ultraviolet-dependent labeling with 2,2,2-trichloroethanol.

Area of Science:

• Biochemistry
• Analytical Chemistry
• Molecular Biology

Background:

• Protein quantification and visualization are essential in biological research.
• Existing methods like UV absorbance and Bradford assay have limitations in sensitivity and dynamic range.
• Fluorescent labeling offers potential for enhanced detection.

Purpose of the Study:

• To develop a sensitive protein quantification assay using 2,2,2-trichloroethanol.
• To enable fluorescent visualization of proteins post-electrophoresis.
• To compare the performance of this new method against established techniques.

Main Methods:

• Utilized 2,2,2-trichloroethanol for covalent modification of tryptophan and tyrosine residues in proteins.
• Developed microplate-based and low-volume assays for protein quantification.
• Applied the method for pre-electrophoresis labeling and visualization of proteins in SDS-PAGE.

Main Results:

• Demonstrated specific fluorescent emission at 450 nm (excitation 310 nm) for 2,2,2-trichloroethanol-labeled proteins.
• Achieved superior sensitivity compared to UV absorbance at 280 nm (A280) and extended quantification range beyond the Bradford method.
• Developed a 100 μL assay with 10.5 μg sensitivity (up to 200 μg) and a 20 μL assay with 8.7 μg sensitivity (up to 100 μg).

Conclusions:

• 2,2,2-trichloroethanol provides a sensitive and versatile tool for protein quantification.
• The method facilitates fluorescent visualization of proteins, aiding in SDS-PAGE analysis.
• This approach offers a valuable alternative to conventional protein assay techniques.