Conjugating Catalytic Polyproline Fragments with a Self-Assembling Peptide Produces Efficient Artificial Hydrolases

Area of Science:

• Biochemistry
• Materials Science
• Enzyme Engineering

Background:

• Designing artificial enzymes with tailored catalytic activity is crucial for various applications.
• Self-assembling peptides offer a versatile platform for creating ordered nanostructures.
• Polyproline-based scaffolds can be engineered to incorporate catalytic functionalities.

Purpose of the Study:

• To design novel hydrolases by conjugating catalytic polyproline fragments with self-assembling peptide MAX1.
• To investigate the structural and catalytic properties of the designed peptides (H2H5 and H2S5).
• To evaluate the potential of these artificial enzymes for ester hydrolysis.

Main Methods:

• Peptide synthesis and coupling of polyproline fragments with MAX1.
• Circular dichroism (CD) and Infrared (IR) spectroscopy to analyze secondary structures.
• Transmission electron microscopy (TEM) and atomic force microscopy (AFM) for structural characterization.
• Enzyme kinetics assays to determine catalytic efficiency on ester substrates.

Main Results:

• Designed peptides (H2H5 and H2S5) self-assemble into network fibrils in solution.
• Peptides exhibit pH-dependent conformational changes from random coils to β-sheets.
• High catalytic efficiency for ester hydrolysis observed at alkaline pH (9.0 and 10.0).
• Demonstrated activity on various ester substrates, including p-nitrophenyl acetate (p-NPA).

Conclusions:

• Combining polyproline-based catalytic units with self-assembling peptides is an effective strategy for designing artificial hydrolases.
• The self-assembled fibrillar structures enhance catalytic efficiency.
• These artificial enzymes represent a new avenue for developing efficient biocatalysts.