GST Antibody

Introduction to GST Antibody

The GST antibody is a critical reagent in molecular biology, designed to detect and purify proteins fused with the glutathione S-transferase (GST) tag. The GST tag, derived from Schistosoma japonicum, is a 26 kDa protein that enhances solubility and stability of recombinant proteins expressed in systems like bacteria or mammalian cells . GST antibodies are used in applications such as Western blotting, immunoprecipitation, and flow cytometry, leveraging the tag’s high affinity for glutathione (GSH) .

Structure and Function of GST Antibody

The GST antibody binds specifically to the GST tag, which is typically fused to the N-terminus of a target protein. Key features include:

• Tag Origin: The GST tag is a homodimer with conserved amino acid sequences, facilitating cross-reactivity across species .

• Applications: Enables detection of tagged proteins without requiring protein-specific antibodies, simplifying workflows .

• Purification Mechanism: GST-tagged proteins bind to glutathione-coated beads, allowing affinity chromatography-based purification .

Table 2: Comparative Analysis of GST Antibodies

Purification Methods Using GST Antibody

The GST tag’s affinity for GSH enables one-step purification via affinity chromatography :

1. Lysis: Prepare cell lysate in buffer containing 1% Triton X-100.

2. Binding: Incubate lysate with glutathione-coated beads (e.g., MagBeads).

3. Elution: Use reduced glutathione (5 mM) to release GST-tagged proteins .

Challenges and Solutions

• Antibody Titre Underestimation: Conventional ELISA using unfused GST underestimates antibody levels by >10-fold. Solution: Use GST-fusion proteins as coating antigens .

• Tag Interference: Large GST tag (26 kDa) may disrupt protein function. Solution: Remove via protease cleavage .