SDS and Protein Denaturation

SDS Effect on Protein Structure

• SDS (Sodium Dodecyl Sulfate) disrupts protein quaternary and tertiary structures, leading to protein denaturation.
• SDS binding causes proteins to unfold, resulting in a loss of their native conformation.

SDS-Protein Interaction

• SDS interacts with proteins through electrostatic forces, specifically binding to positively charged amino acid residues.
• The negative charge of SDS molecules interacts with the positive charge of proteins, resulting in a neutralization of the protein's charge.

Outcome of SDS Coating

• The coating of negatively charged SDS on proteins masks their native charge, resulting in a uniform negative charge.
• This uniform charge allows proteins to be separated based on their size, rather than their charge.

Electrophoresis Principle

• Electrophoresis is a separation technique based on the migration of charged particles in an electric field.
• Particles with a net charge will move towards the oppositely charged electrode.

Zone Electrophoresis

• The purpose of the stabilizing medium in zone electrophoresis is to maintain the pH and ionic strength of the system.
• The stabilizing medium helps to prevent protein-protein and protein-matrix interactions, ensuring that proteins migrate solely based on their size.

Gel Electrophoresis

• pH affects the charge and migration of proteins in gel electrophoresis.
• The buffer in gel electrophoresis maintains the pH and ionic strength of the system, ensuring that proteins migrate consistently and accurately.
• The buffer also helps to maintain the stability and integrity of the gel matrix.