Hydrophobic Protein Separation
Hydrophobic Protein Separation - Related Videos
07:29
Separating Protein with SDS-PAGE
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2023
Sodium Dodecyl Sulfate Poly-Acrylamide Gel Electrophoresis, or SDS-PAGE, is a widely-used technique for separating mixtures of proteins based on their size and nothing else. SDS, an anionic detergent, is used to produce an even charge across the length of proteins that have been linearized. By first loading them into a gel made of polyacrylamide and then applying an electric field to the gel, SDS-coated proteins are then separated. The electric field acts as the driving force, drawing the SDS...
03:22
Calcium-Dependent Hydrophobic Interaction Chromatography: A Technique to Purify Calcium-Binding Proteins Based on Hydrophobic Interactions
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2025
In this video, we demonstrate the purification of calcium-binding protein from a dialyzed cell lysate through calcium-dependent hydrophobic interaction chromatography. The calcium-binding proteins expose a hydrophobic region upon binding with calcium, facilitating interaction with a hydrophobic group on resin. Later these proteins are eluted using calcium chelator EDTA that reverses the interaction.
08:17
Electrophoretic Separation of Proteins
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Cited by 29 •
2008
In this video, we demonstrate a method for electrophoretic separation of proteins using poly-acrylimide gel electrophoresis (PAGE).
10:21
Automated Hydrophobic Interaction Chromatography Column Selection for Use in Protein Purification
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Cited by 17 •
2011
An automated method for identifying suitable hydrophobic interaction chromatography (HIC) media to be used in the process of protein purification is presented. The method utilizes a medium-pressure liquid chromatography system including automated buffer blending, dynamic sample loop injection, sequential column selection, multi-wavelength analysis, and split fraction eluate collection.
06:14
Separation and Fractionation of Cell Wall and Cell Membrane Proteins from Mycobacterium tuberculosis for Downstream Protein Analysis
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2025
This protocol separates insoluble cell wall and membrane proteins into simple fractions (1-5 proteins) using preparative isoelectric focusing (IEF) based on isoelectric point, followed by separation by molecular weight. The resulting fractions can be used directly for immunological and proteomic analysis without further purification.
FAQs
High-salt conditions strengthen hydrophobic interactions between exposed nonpolar regions of proteins and mildly hydrophobic ligands on the stationary phase. As the salt concentration is gradually lowered, those interactions weaken, allowing bound proteins to leave the stationary phase. Differences in binding strength therefore determine when proteins appear in separate elution fractions.
These changes can alter which nonpolar surface regions are exposed, changing a protein’s interaction with the stationary phase. A folded protein, a newly formed complex, or a chemically modified molecule may therefore bind differently from its original form. Comparing separation behavior can help reveal structural or surface changes relevant to protein characterization.
Elution depends on the relative strength of each protein’s hydrophobic interaction with the stationary-phase ligand under the selected salt conditions. Proteins that lose this interaction earlier appear in earlier fractions, whereas more strongly retained proteins elute as salt reduction continues. The resulting pattern separates proteins according to differences in exposed nonpolar surface properties.
The process first places the protein mixture under high-salt conditions so proteins can interact with mildly hydrophobic ligands on the stationary phase. The salt concentration is then reduced gradually, weakening those interactions and releasing proteins at different points. Researchers collect the resulting fractions separately for further structural or functional analysis.
This approach is useful when investigators need to isolate immune-related proteins according to differences in exposed nonpolar surfaces. The source material specifically identifies antibodies and antigens as applications, along with other proteins associated with infection studies. Purified fractions can support subsequent structural and functional analysis of these molecules.
The fractions can show how proteins differ in surface hydrophobicity, not merely whether they were isolated. Changes in elution behavior may reflect folding, complex formation, or chemical modification. In immunology and infection research, that information can help connect altered protein surfaces with the structural or functional properties being examined.