TrypEnviron

🔍 Reference Wavelengths

Free Tryptophan in Water: ~350-355 nm

Buried in Protein: ~330-335 nm

Partially Exposed: ~340-345 nm

Note: Exact values depend on local environment and protein structure

🔴 Red Shift (Higher λmax)

Indicates: More polar environment

• Tryptophan becoming more exposed to solvent
• Protein unfolding or conformational change
• Increased accessibility to water molecules
• Loss of hydrophobic interactions

Example: 335 nm → 345 nm = 10 nm red shift

🔵 Blue Shift (Lower λmax)

Indicates: More hydrophobic environment

• Tryptophan becoming more buried
• Protein folding or compaction
• Decreased solvent accessibility
• Increased hydrophobic interactions

Example: 345 nm → 335 nm = 10 nm blue shift

📊 Practical Applications

• Protein folding studies: Monitor folding transitions
• Denaturation experiments: Track unfolding processes
• Ligand binding: Detect conformational changes
• pH effects: Study ionization-induced changes
• Temperature studies: Thermal stability analysis

⚠️ Important Considerations

• Multiple tryptophans: Results represent average environment
• Energy transfer: May affect observed wavelengths
• pH effects: Ionization can influence fluorescence
• Temperature: Can affect both structure and fluorescence
• Significance: Shifts >2-3 nm typically meaningful

🎯 Experimental Tips

• Controls: Always include native protein reference
• Replicates: Perform multiple measurements
• Buffer effects: Keep ionic strength consistent
• Concentration: Use consistent protein concentrations
• Time course: Monitor changes over time if relevant