Two Engineered OBPs with opposite temperature-dependent affinities towards 1-aminoanthracene

Area of Science:

• Biochemistry
• Molecular Biology
• Protein Engineering

Background:

• Odorant-binding proteins (OBPs) are crucial for olfaction.
• Engineering OBPs can create novel functionalities.
• Temperature-sensitive molecular interactions are of significant interest.

Purpose of the Study:

• To engineer OBPs with temperature-tunable binding affinities.
• To investigate the mechanism of temperature-dependent ligand binding in engineered OBPs.
• To demonstrate a competitive, temperature-controlled binding system.

Main Methods:

• Design and production of engineered OBPs (tOBP and OBP::GQ20::SP-DS3).
• Measurement of 1-aminoanthracene (1-AMA) binding affinities at different temperatures (25°C and 37°C).
• Molecular modeling to analyze binding pocket variations.

Main Results:

• tOBP exhibited higher 1-AMA affinity at 25°C (Kd = 0.45 μM) than at 37°C (Kd = 1.72 μM).
• OBP::GQ20::SP-DS3 showed reversed behavior with higher affinity at 37°C (Kd = 0.58 μM) than at 25°C (Kd = 1.17 μM).
• Differential and reversible 1-AMA binding was confirmed, driven by temperature-induced changes in binding pocket size.

Conclusions:

• Engineered OBPs can exhibit tunable, temperature-dependent binding affinities.
• This study presents a novel competitive temperature-dependent mechanism for OBPs.
• The findings open avenues for temperature-controlled molecular recognition systems.