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Cited by 14Metal-Catalyzed Oxygenation Mechanismsmelanin and skin pigmentationEnzyme-mediated dye degradation

New inhibitors of laccase and tyrosinase by examination of cross-inhibition between copper-containing enzymes

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Chaudhary, Dinesh, Chong, Fangchen, Neupane, Trilok, Choi, Joonhyeok, Jee, Jun-Goo·2021·International Journal of Molecular Sciences
DOI 10.3390/ijms222413661PMC PMC8707586
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Abstract

Coppers play crucial roles in the maintenance homeostasis in living species. Approximately 20 enzyme families of eukaryotes and prokaryotes are known to utilize copper atoms for catalytic activities. However, small-molecule inhibitors directly targeting catalytic centers are rare, except for those that act against tyrosinase and dopamine-β-hydroxylase (DBH). This study tested whether known tyrosinase inhibitors can inhibit the copper-containing enzymes, ceruloplasmin, DBH, and laccase. While most small molecules minimally reduced the activities of ceruloplasmin and DBH, aside from known inhibitors, 5 of 28 tested molecules significantly inhibited the function of laccase, with the Ki values in the range of 15 to 48 µM. Enzyme inhibitory kinetics classified the molecules as competitive inhibitors, whereas differential scanning fluorimetry and fluorescence quenching supported direct bindings. To the best of our knowledge, this is the first report on organic small-molecule inhibitors for laccase. Comparison of tyrosinase and DBH inhibitors using cheminformatics predicted that the presence of thione moiety would suffice to inhibit tyrosinase. Enzyme assays confirmed this prediction, leading to the discovery of two new dual tyrosinase and DBH inhibitors.

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  • Certain inhibitors bind to the copper ion active center of LAC, decreasing its oxidizing capacity.

    “For example, certain inhibitors bind to the copper ion active center of LAC, decreasing its oxidizing capacity.”

    From Fungal Melanin in Plant Pathogens: Complex Biosynthesis Pathways and Diverse Biological Functions (2025) · cites this paper as [94]

    The Results (§2.2–2.3; page unavailable) report that the inhibitors reduce laccase activity and bind directly to the enzyme. But the Discussion (§3; page unavailable) only proposes copper chelation as a possible mechanism for captopril; it says the inhibitors’ binding sites remain unresolved. The claim presents binding at the copper active center as established. (LLM, conf=0.88)

    Experimental — accuracy not yet measured

  • Even if melanin precursors are synthesized normally, inhibitors can target enzymes involved in the oxidative polymerization step, such as LAC or tyrosinase, to prevent the final formation of melanin.

    “Even if melanin precursors are synthesized normally, inhibitors can target enzymes involved in the oxidative polymerization step, such as LAC or tyrosinase, to prevent the final formation of melanin [94,95].”

    From Fungal Melanin in Plant Pathogens: Complex Biosynthesis Pathways and Diverse Biological Functions (2025) · cites this paper as [94]

    The Introduction identifies tyrosinase as important to melanin production, and the Results report inhibitors of both tyrosinase and laccase. But the Introduction places tyrosinase in the conversion of tyrosine to DOPA and dopaquinone, before spontaneous conversion to melanin. The paper does not establish that inhibiting either enzyme prevents final melanin formation when precursors have been synthesized normally. (LLM, conf=0.86)

    Experimental — accuracy not yet measured

  • This prevents the oxidative polymerization of DHN into melanin, thereby attenuating pathogen virulence.

    “This prevents the oxidative polymerization of DHN into melanin, thereby attenuating pathogen virulence.”

    From Fungal Melanin in Plant Pathogens: Complex Biosynthesis Pathways and Diverse Biological Functions (2025) · cites this paper as [94]

    The Introduction (page unavailable) describes melanin formation through the tyrosinase–DOPA pathway, not oxidative polymerization of DHN. Searches for DHN, fungal melanin, and pathogen virulence found no passage in our copy addressing whether preventing that polymerization attenuates virulence. (LLM, conf=0.72)

    Experimental — accuracy not yet measured

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Cited by

Sorted by citations

Authors
Chaudhary, D., Chong, F., Neupane, T., Choi, J., & Jee, J.-G.
Affiliations
Kyungpook National University (KR)
Corresponding author
Jee, Jun-Goo
ORCID
Venue
International Journal of Molecular Sciences
Publisher
MDPI AG
Published
2021-12-20
Volume
22
Issue
24
Pages
13661
ISSN
1422-0067 (ISSN-L)
DOI
10.3390/ijms222413661
PMC
PMC8707586
OpenAlex
W4200481871
Cited by
14
References
2
Citations by year
2026: 4 · 2025: 3 · 2024: 4 · 2022: 3
FWCI
0.57
Type
journal article
Language
en
Open access
Licence
Locations
  • International Journal of Molecular Sciences (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
  • the 4TH BK21 project (Educational Research Group for Platform development of management of emerging infectious disease) of the Korean ministry of education (5199990614732)
  • the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science & ICT (2017M3A9G8083382)
Topics
  • Physical Sciences › Chemistry › Inorganic Chemistry › Metal-Catalyzed Oxygenation Mechanisms
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cell Biology › melanin and skin pigmentation
  • Life Sciences › Agricultural and Biological Sciences › Plant Science › Enzyme-mediated dye degradation
Keywords
tyrosinase inhibitors, dopamine beta-hydroxylase inhibitor, cross-inhibition, copper enzymes, ceruloplasmin, competitive inhibition, dual enzyme inhibitors, small molecule inhibitors, enzyme binding
MeSH terms
Cheminformatics, Agaricales, Ceruloplasmin, Copper, Dopamine beta-Hydroxylase, Enzyme Inhibitors, Fungal Proteins, Fungi, Humans, Models, Molecular, Protein Conformation, Catalytic Domain, Laccase, Small Molecule Libraries, Biocatalysis

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