Characterization of Temperature-Dependent Kinetics of Oculocutaneous Albinism-Causing Mutants of Tyrosinase

Wachamo, Samuel A.; Patel, Mayank; Dolinska, Monika B.; Sergeev, Yuri V.

doi:10.3390/ijms22157771

Cited by 4 publications

(5 citation statements)

References 31 publications

(68 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Tyrosinase (TYR) is the key rate-limiting enzyme in the process of melanogenesis, and TYR activity strongly affects the entire pigmentation process [ 27 ]. The higher activity of TYR could lead to a higher amount of melanogenesis.…”

Section: Resultsmentioning

confidence: 99%

Evaluating the Application Potential of a Recombinant Ganoderma Protein as Bioactive Ingredients in Cosmetics

et al. 2023

View full text Add to dashboard Cite

The aim of this study was to evaluate the application potential of a recombinant fungal immunomodulatory protein from Ganoderma lucidum (rFIP-glu). First, a recombinant plasmid pPIC9K::FIP-glu-His was transferred into Pichia pastoris for the production of protein. The protein was then to assess its free radical scavenging abilities and the effect on the viability of both human immortalized keratinocytes (HaCaT cells) and mouse B16-F10 melanoma cells (B16 cells) in vitro, followed by the effect on the melanin synthesis of B16 cells. The results of SDS-PAGE and western blot showed that rFIP-glu was successfully expressed. Furtherly, a bioactivity assay in vitro indicated that the scavenging rate of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals reached 84.5% at 6.0 mg/mL (p ≤ 0.0001) of rFIP-glu, showing strong antioxidant activity. Subsequently, a safety evaluation demonstrated that rFIP-glu promoted the proliferation of HaCaT cells, with the cell viability reaching 124.3% at 48 μg/mL (p ≤ 0.01), regarding the cell viability of B16 cells after exposure to rFIP-glu (48 μg/mL) significantly inhibited, to 80.7% (p ≤ 0.01). Besides, rFIP-glu inhibited the melanin synthesis of B16 cells in a dose-dependent manner from 100–1000 μg/mL, and rFIP-glu at 500 μg/mL (p ≤ 0.01) exhibited the highest intracellular melanin amount reduction of 16.8%. Furthermore, a mechanism analysis showed that rFIP-glu inhibited tyrosinase (TYR) activity by up-regulating the expression of the microphthalmia-associated transcription factor (MITF) and down-regulating the gene expression of TYR and tyrosinase-related protein-1 (TYRP-1), thus inhibiting melanin synthesis. The data implied that rFIP-glu had significant antioxidant activity and whitening potency. It should be used as raw materials for cosmeceutical applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Evaluating the Application Potential of a Recombinant Ganoderma Protein as Bioactive Ingredients in Cosmetics

et al. 2023

View full text Add to dashboard Cite

show abstract

“…For example, the squalene epoxidase catalyzing the first oxygenation step in the triterpenoid and phytosterol biosynthetic pathway is one of the key enzymes in this pathway ( Gao et al, 2016 ). Tyrosinase catalyzed both the first and key step in melanin production ( Wachamo et al, 2021 ). PGM catalyzed the branch point reaction-the interconversion of glucose-1-phosphate from glucose-6-phosphate in carbohydrate metabolism.…”

Section: Resultsmentioning

confidence: 99%

Identification of the Key Enzymes in WL Gum Biosynthesis and Critical Composition in Viscosity Control

Zhang

Liu

et al. 2022

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

As an important microbial exopolysaccharide, the sphingan WL gum could be widely used in petroleum, food, and many other fields. However, its lower production is still limiting its wider application. Therefore, to gain insights into the bottlenecks of WL gum production by identifying the key enzymes in the WL gum biosynthesis pathway, more than 20 genes were over-expressed in Sphingomonas sp. WG and their effects on WL gum production and structure were investigated. Compared to the control strain, the WL gum production of welB over-expression strain was increased by 19.0 and 21.0% at 36 and 84 h, respectively. The WL gum production of both atrB and atrD over-expression strains reached 47 g/L, which was approximately 34.5% higher than that of the control strain at 36 h. Therefore, WelB, AtrB, and AtrD may be the key enzymes in WL production. Interestingly, the broth viscosity of most over-expression strains decreased, especially the welJ over-expression strain whose viscosity decreased by 99.3% at 84 h. Polysaccharides’ structural features were investigated to find the critical components in viscosity control. The uronic acid content and total sugar content was affected by only a few genes, therefore, uronic acid and total sugar content may be not the key composition. In comparison, the acetyl degrees were enhanced by over-expression of most genes, which meant that acetyl content may be the critical factor and negatively correlated with the apparent viscosity of WL gum. This work provides useful information on the understanding of the bottlenecks of WL gum biosynthesis and will be helpful for the construction of high WL gum-yielding strains and rheological property controlling in different industries.

show abstract

“…In P406L, the OCA1B-related mutation in tyrosinase significantly impacts small-molecule substrate binding. We previously showed that the association of L-DOPA with R422Q and P406L mutant variants followed by dopachrome formation is a complex reaction supported by enthalpic and entropic forces [ 17 , 18 ]. rTyr has a higher turnover number as compared with both R422Q and P406L.…”

Section: Discussionmentioning

confidence: 99%

“…Although we saw a change in rTyr activity in R422Q and P406L mutant variants, we found similar Km values and thermodynamic behavior for other proteins. This led us to deduce that the change in activity might be due to the allosteric effect [ 18 , 29 ]. Utilizing molecular docking and MD simulations, we demonstrated that, in a water environment, only DHI docked with proper orientation to P406L’s active site and then remained stable after MD simulations ( Figure S3 ).…”

Section: Discussionmentioning

confidence: 99%

“…Previously, we utilized rTyr and several OCA1-related mutant variants to analyze tyrosinase binding during its diphenol oxidase reaction [ 17 , 18 ]. Van’t Hoff temperature-dependent analysis suggested that the association of L-DOPA with rTyr is a spontaneous enthalpy-driven reaction and becomes unfavorable at the final step of dopachrome formation.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular Modeling of the Multiple-Substrate Activity of the Human Recombinant Intra-Melanosomal Domain of Tyrosinase and Its OCA1B-Related Mutant Variant P406L

Dolinska,

Sergeev

2024

IJMS

Self Cite

View full text Add to dashboard Cite

Tyrosinase serves as the key enzyme in melanin biosynthesis, catalyzing the initial steps of the pathway, the hydroxylation of the amino acid L-tyrosine into L-3,4-dihydroxyphenylalanine (L-DOPA), followed by the subsequent oxidation of L-DOPA into dopaquinone (DQ), and it facilitates the conversion of 5,6-dihydroxyindole-2-carboxylic acid (DHICA) into 5,6-indolequinone-2-carboxylic acid (IQCA) and 5,6-dihydroxy indole (DHI) into indolequinone (IQ). Despite its versatile substrate capabilities, the precise mechanism underlying tyrosinase’s multi-substrate activity remains unclear. Previously, we expressed, purified, and characterized the recombinant intra-melanosomal domain of human tyrosinase (rTyr). Here, we demonstrate that rTyr mimics native human tyrosinase’s catalytic activities in vitro and in silico. Molecular docking and molecular dynamics (MD) simulations, based on rTyr’s homology model, reveal variable durability and binding preferences among tyrosinase substrates and products. Analysis of root mean square deviation (RMSD) highlights the significance of conserved residues (E203, K334, F347, and V377), which exhibit flexibility during the ligands’ binding. Additionally, in silico analysis demonstrated that the OCA1B-related P406L mutation in tyrosinase substantially influences substrate binding, as evidenced by the decreased number of stable ligand conformations. This correlation underscores the mutation’s impact on substrate docking, which aligns with the observed reduction in rTyr activity. Our study highlights how rTyr dynamically adjusts its structure to accommodate diverse substrates and suggests a way to modulate rTyr ligand plasticity.

show abstract

Characterization of Temperature-Dependent Kinetics of Oculocutaneous Albinism-Causing Mutants of Tyrosinase

Cited by 4 publications

References 31 publications

Evaluating the Application Potential of a Recombinant Ganoderma Protein as Bioactive Ingredients in Cosmetics

Evaluating the Application Potential of a Recombinant Ganoderma Protein as Bioactive Ingredients in Cosmetics

Identification of the Key Enzymes in WL Gum Biosynthesis and Critical Composition in Viscosity Control

Molecular Modeling of the Multiple-Substrate Activity of the Human Recombinant Intra-Melanosomal Domain of Tyrosinase and Its OCA1B-Related Mutant Variant P406L

Contact Info

Product

Resources

About