A molecularly imprinted polymer-based synthetic transaminase

Area of Science:

• Biomimetic Chemistry
• Polymer Science
• Enzyme Catalysis

Background:

• Transaminases are crucial enzymes for amino acid synthesis.
• Developing artificial mimics with catalytic activity and selectivity is challenging.
• Molecular imprinting offers a route to create tailored polymer catalysts.

Purpose of the Study:

• To design, synthesize, and evaluate a molecularly imprinted polymer (MIP) as a transaminase mimic.
• To investigate the catalytic activity and enantioselectivity of the MIP.
• To explore the potential of MIPs in catalyzing sigmatropic shifts.

Main Methods:

• Synthesis of methacrylic acid-ethylene glycol dimethacrylate copolymers using a transition state analogue (TSA) template.
• (1)H NMR studies to assess template-functional monomer interactions.
• High-Performance Liquid Chromatography (HPLC) for evaluating recognition and enantioseparation.
• Kinetic studies to determine catalytic parameters (Vmax, Km, kcat).

Main Results:

• The MIP exhibited selectivity for the TSA over substrates and products in both aqueous and nonpolar media.
• Enantioseparation factor (alpha) of 2.1 was achieved in chloroform/acetic acid.
• The polymer demonstrated a 15-fold enhancement in apparent reaction rate and enantioselective phenylalanine production (32% ee).
• A turnover number (kcat) of 0.1 s(-1) was determined.

Conclusions:

• This study presents the first example of molecularly imprinted polymers catalyzing sigmatropic shifts in aqueous media.
• The developed MIP functions as an effective transaminase mimic with significant catalytic enhancement and enantioselectivity.
• Molecular imprinting is a viable strategy for creating artificial enzymes with tailored catalytic functions.