title: Enzyme-Mimic Peptide Assembly To Achieve Amidolytic Activity.
abstract: Amyloid fibers are classified as a new generation of tunable bionanomaterials that exhibit new functions related to their distinctive characteristics, such as their universality, tunability, and stiffness. Here, we introduce the catalytic residues of serine protease into a peptide catalyst (PC) via an enzyme-mimic approach. The rational design of a repeating pattern of polar and nonpolar amino acids favors the conversion of the peptides into amyloid-like fibrils via self-assembly. Distinct fibrous morphologies have been observed at different pH values and temperatures, which indicates that different fibril packing schemes can be designed; hence, fibrillar peptides can be used to generate efficient artificial catalysts for amidolytic activities at mild pH values. The results of atomic force microscopy, Raman spectroscopy, and wide-angle X-ray scattering analyses are used to discuss and compare the fibril structure of a fibrillar PC with its amidolytic activity. The pH of the fibrillation reaction crucially affects the pKaof the side chains of the catalytic triads and is important for stable fibril formation. Temperature is another important parameter that controls the self-assembly of peptides into highly stacked and laminated morphologies. The morphology and stability of fibrils are crucial and represent important factors for demonstrating the capability of the peptides to exert amidolytic activity. The observed amidolytic activity of PC4, one of the PCs, was validated using an inhibition assay, which revealed that PC4 can perform enzyme-like amidolytic catalysis. These results provide insights into the potential use of designed peptides in the generation of efficient artificial enzymes.
authors.affiliation: Enzyme Research Team, RIKEN Center for Sustainable Resource Science , 2-1, Hirosawa, Wako-shi, Saitama 351-0198, Japan.|Ecobiomaterial Research Laboratory, School of Biological Sciences, Universiti Sains Malaysia , 11800, Minden, Penang, Malaysia.
authors.forename: Yoke-Ming
authors.initials: YM
authors.lastname: Wong
authors.affiliation: Japan Synchrotron Radiation Research Institute, 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Masunaga
authors.affiliation: Enzyme Research Team, RIKEN Center for Sustainable Resource Science , 2-1, Hirosawa, Wako-shi, Saitama 351-0198, Japan.
authors.forename: Jo-Ann
authors.initials: JA
authors.lastname: Chuah
authors.affiliation: Ecobiomaterial Research Laboratory, School of Biological Sciences, Universiti Sains Malaysia , 11800, Minden, Penang, Malaysia.
authors.forename: Kumar
authors.initials: K
authors.lastname: Sudesh
authors.affiliation: Enzyme Research Team, RIKEN Center for Sustainable Resource Science , 2-1, Hirosawa, Wako-shi, Saitama 351-0198, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Numata
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry* / Q000648:ultrastructure; D016229:Amyloid beta-Peptides / Q000737:chemistry* / Q000648:ultrastructure; D002384:Catalysis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D017433:Protein Structure, Secondary; D057057:Serine Proteases / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013696:Temperature
chemical_list: D000682:Amyloid; D016229:Amyloid beta-Peptides; D057057:Serine Proteases