Affinity partitioning: a new approach for studying dye-protein interactions.

Area of Science:

• Biochemistry
• Analytical Chemistry
• Separation Science

Background:

• Proteins exhibit specific affinities for various molecules, including dyes.
• Aqueous two-phase systems offer a platform for studying these interactions.
• Understanding protein-dye binding is crucial for biochemical analysis and purification.

Purpose of the Study:

• To quantify the affinity of specific proteins (phosphofructokinase, glucose-6-phosphate dehydrogenase, albumin, prealbumin) to reactive dyes.
• To investigate protein-protein interactions in the presence of dyes using affinity partitioning.
• To demonstrate the utility of affinity partitioning for studying competitive ligand binding.

Main Methods:

• Utilized affinity partitioning in an aqueous two-phase system (dextran and dye-liganded polyethylene glycol).
• Measured changes in the partition coefficient (delta log K) to determine protein-dye affinity.
• Investigated protein interactions by observing changes in partitioning behavior.

Main Results:

• Quantitative data on the maximal extraction power and affinity of proteins to reactive dyes were obtained.
• An increased affinity partitioning effect for prealbumin in the presence of excess monomeric albumin and Remazol Yellow GGL dye was observed, indicating protein-protein interaction.
• The competitive binding of natural ligands to reactive dyes was successfully demonstrated for phosphofructokinase and prealbumin.

Conclusions:

• Affinity partitioning is an effective method for quantifying protein-dye affinities and studying protein-ligand interactions.
• Albumin and prealbumin exhibit distinct binding behaviors with reactive dyes.
• The presence of dyes can modulate or reveal protein-protein interactions.