CATCH Peptides Coassemble into Structurally Heterogeneous β-Sheet Nanofibers with Little Preference to β-Strand...

Area of Science:

• Biomaterials Science
• Nanotechnology
• Structural Biology

Background:

• Coassembling peptides offer enhanced control over nanostructured biomaterials compared to self-assembling peptides.
• Limited understanding exists regarding how amino acid sequences dictate coassembled nanofiber structures.
• Previous studies on CATCH peptides revealed self-associated nearest neighbors, deviating from ideal coassembly.

Purpose of the Study:

• To investigate the structural heterogeneity and β-strand alignment within coassembled CATCH peptide nanofibers.
• To compare the structural characteristics of CATCH nanofibers with other coassembling systems like King-Webb peptides.
• To identify sequence-to-structure relationships governing precise coassembled β-sheet nanostructures.

Main Methods:

• Solid-state Nuclear Magnetic Resonance (NMR) spectroscopy.
• Isotope-edited Fourier-Transform Infrared (FTIR) spectroscopy.
• Coarse-grained molecular dynamics (MD) simulations.

Main Results:

• CATCH peptides coassemble into structurally heterogeneous nanofibers, confirmed by both experimental and computational approaches.
• Within β-sheet nanofibers, β-strands exhibit varied nearest-neighbor alignments: in-register parallel, in-register antiparallel, and out-of-register.
• CATCH nanofibers display greater structural heterogeneity compared to King-Webb peptide nanofibers.

Conclusions:

• Coassembled CATCH peptide nanofibers are structurally heterogeneous, with diverse β-strand alignments.
• Comparing CATCH and King-Webb peptide sequences provides insights into sequence-encoded structural control.
• Further unraveling these sequence-structure relationships is crucial for designing precise coassembled β-sheet nanostructures.