Phenylgalactoside CAS:2818-58-8

Effect on enzyme activity: Phenylgalactoside is commonly used to measure the activity of the enzyme β-galactosidase. When phenylgalactoside is hydrolyzed by β-galactosidase, it releases p-nitrophenol. The accumulation of p-nitrophenol can be quantitatively measured, providing insights into the activity of β-galactosidase. This effect is harnessed in applications such as enzyme assays and screening systems.

Gene expression analysis: Phenylgalactoside is often used as a substrate in molecular biology experiments to study gene expression. The lacZ gene, which encodes β-galactosidase, is commonly fused with regulatory sequences of other genes of interest. The expression of the lacZ gene and the hydrolysis of phenylgalactoside by β-galactosidase can indicate the expression pattern and level of the target gene being studied.

Screening systems: Phenylgalactoside is an important component of screening systems that make use of β-galactosidase activity. One widely known example is the blue-white screening method, which is used to identify recombinant or transformed cells in molecular biology experiments. Colonies that have successfully taken up the recombinant DNA or undergone genetic recombination will express β-galactosidase, leading to the hydrolysis of phenylgalactoside and the formation of a blue color.

Protein purification: In some cases, phenylgalactoside can be used as a ligand for affinity chromatography to purify proteins that specifically bind to or are activated by β-galactosidase. The protein of interest may have an affinity tag or a fusion tag containing a β-galactosidase-binding domain. By passing the protein mixture through a column with immobilized phenylgalactoside, the desired protein can be selectively retained and subsequently eluted.