ArticleScientific reports2020
Conversion of walnut tyrosinase into a catechol oxidase by site directed mutagenesis.
Article in Scientific reports, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 18 papers.
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18 citing papers in PubMed, 38 citations in OpenAlex.
- In silico and in vitro exploration of a tyrosinase for biocatalytic production of catechols.FEBS open bio · 2026Article
- The Walnut's Dark Secret: Polyphenol Oxidase and the Enigmatic Pathway to Melanin.International journal of molecular sciences · 2026Review
- Article
- Biochemical Analysis of Recombinant Pea Seed Coat-Specific Polyphenol Oxidase (Journal of agricultural and food chemistry · 2025Article
- Coupled Binuclear Copper Sites in Biology: An Experimentally-Calibrated Computational Perspective.Coordination chemistry reviews · 2025Article
- Novel Hybrid Catalysts of Cysteine Proteases Enhanced by Chitosan and Carboxymethyl Chitosan Micro- and Nanoparticles.Polymers · 2024Article
- Tyrosinases: a family of copper-containing metalloenzymes.Chemtexts · 2024Article
- Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide.Beilstein journal of organic chemistry · 2024Article
- Computer-aided design and implementation of efficient biosynthetic pathways to produce high added-value products derived from tyrosine inFrontiers in bioengineering and biotechnology · 2024Article
- Emerging functions within the enzyme families of plant alkaloid biosynthesis.Phytochemistry reviews : proceedings of the Phytochemical Society of Europe · 2023Article
- Biochemical Investigations of Five Recombinantly Expressed Tyrosinases Reveal Two Novel Mechanisms Impacting Carbon Storage in Wetland Ecosystems.Environmental science & technology · 2023Article
- The Crystal Structure of Tyrosinase fromBiomolecules · 2023Article
- Recent Advances of Polyphenol Oxidases in Plants.Molecules (Basel, Switzerland) · 2023Review
- Olive Polyphenol Oxidase Gene Family.International journal of molecular sciences · 2023Article
- Polyphenol oxidase and enzymatic browning in apricot (Current research in food science · 2022Article
- Oxidation-Induced "One-Pot" Click Chemistry.Chemical reviews · 2021Article
- Similar but Still Different: Which Amino Acid Residues Are Responsible for Varying Activities in Type-III Copper Enzymes?Chembiochem : a European journal of chemical biology · 2021Review
- Identification of Amino Acid Residues Responsible for C-H Activation in Type-III Copper Enzymes by Generating Tyrosinase Activity in a Catechol Oxidase.Angewandte Chemie (International ed. in English) · 2020Article
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4 authors at 1 institution in 1 country.
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Abstract
Polyphenol oxidases (PPOs) comprise tyrosinases (TYRs) and catechol oxidases (COs), which catalyse the initial reactions in the biosynthesis of melanin. TYRs hydroxylate monophenolic (monophenolase activity) and oxidize diphenolic (diphenolase activity) substrates, whereas COs react only with diphenols. In order to elucidate the biochemical basis for the different reactions in PPOs, cDNA from walnut leaves was synthesized, the target gene encoding the latent walnut tyrosinase (jrPPO1) was cloned, and the enzyme was heterologously expressed in Escherichia coli. Mutations targeting the two activity controller residues (Asn240 and Leu244) as well as the gatekeeper residue (Phe260) were designed to impair monophenolase activity of jrPPO1. For the first time, monophenolase activity of jrPPO1 towards L-tyrosine was blocked in two double mutants (Asn240Lys/Leu244Arg and Asn240Thr/Leu244Arg) while its diphenolase activity was partially preserved, thereby converting jrPPO1 into a CO. Kinetic data show that recombinant jrPPO1 resembles the natural enzyme, and spectrophotometric investigations proved that the copper content remains unaffected by the mutations. The results presented herein provide experimental evidence that a precisely tuned interplay between the amino acids located around the active center controls the substrate specificity and therewith the mono- versus diphenolase activity in the type-III copper enzyme jrPPO1.
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