Intrinsic enzymatic properties modulate the self-propulsion of micromotors

• Published in: Nature communications 2019-06, Vol.10 (1), p.2826-12, Article 2826
• Main Authors: Arqué, Xavier, Romero-Rivera, Adrian, Feixas, Ferran, Patiño, Tania, Osuna, Sílvia, Sánchez, Samuel
• Format: Article
• Language: English
• Subjects: 147/135; 147/143; 147/28; 631/45/607/1162; 639/301/357/339; 639/638/77/603; Acetylcholinesterase; Acetylcholinesterase - chemistry; Aldolase; Animals; Aspergillus niger - enzymology; Biocatalysis; Canavalia - enzymology; Catalysis; Catalytic converters; Electrophorus; Enzymes; Enzymes, Immobilized - chemistry; Fish Proteins - chemistry; Fructose-Bisphosphate Aldolase - chemistry; Fungal Proteins - chemistry; Glucose oxidase; Glucose Oxidase - chemistry; Humanities and Social Sciences; Kinetics; Microcapsules; Micromotors; Molecular dynamics; multidisciplinary; Nanostructures - chemistry; Plant Proteins - chemistry; Propulsion; Protein Conformation; Rabbits; Rigidity; Science; Science (multidisciplinary); Silica; Silicon dioxide; Silicon Dioxide - chemistry; Substrates; Urease; Urease - chemistry
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-10726-8

Bio-catalytic micro- and nanomotors self-propel by the enzymatic conversion of substrates into products. Despite the advances in the field, the fundamental aspects underlying enzyme-powered self-propulsion have rarely been studied. In this work, we select four enzymes (urease, acetylcholinesterase, glucose oxidase, and aldolase) to be attached on silica microcapsules and study how their turnover number and conformational dynamics affect the self-propulsion, combining both an experimental and molecular dynamics simulations approach. Urease and acetylcholinesterase, the enzymes with higher catalytic rates, are the only enzymes capable of producing active motion. Molecular dynamics simulations reveal that urease and acetylcholinesterase display the highest degree of flexibility near the active site, which could play a role on the catalytic process. We experimentally assess this hypothesis for urease micromotors through competitive inhibition (acetohydroxamic acid) and increasing enzyme rigidity (β-mercaptoethanol). We conclude that the conformational changes are a precondition of urease catalysis, which is essential to generate self-propulsion. Self-propulsion of biocatalytic micro- and nanomotors is facilitated by enzymes converting substrates into products. Here, the authors show that intrinsic enzymatic properties such as conformational changes are crucial for the self-propulsion of silica microcapsules modified with urease.