Tyrosinase Activated Melanoma Prodrugs

Jawaid, Samaila; Khan, Taseer Ahmed; Osborn, Helen M. I.; Williams, Nana Aba

doi:10.2174/187152009789056886

Cited by 39 publications

(22 citation statements)

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“…Synthetic studies provide models of both complexes and evidence for rapid equilibrium between the two forms [3]. The monophenol hydroxylase and diphenoloxidase activities of tyrosinases are the basis for many industrial biotechnological applications like in environmental technology for the detoxification of phenol-containing waste waters and contaminated soils as a construction of a biosensor for the detaction of phenolic compound [4] and in pharmaceutical industries for the production of o -diphenols (e.g., L-DOPA, dopamine for the treatment of Parkinson's disease) and also have been tested as a marker in melanoma patients [5] and as a target for the activation of prodrugs [6] in food industries for modification of food proteins via crosslinking affects [7]. Synthetic melanin is also used for protection against radiation (UV, X-ray, and gamma ray), cation exchangers, drug carriers, antioxidants, antiviral agents, or immunogen.…”

Section: Introductionmentioning

confidence: 99%

Microbial Tyrosinases: Promising Enzymes for Pharmaceutical, Food Bioprocessing, and Environmental Industry

Zaidi

Ali²,

Ali³

et al. 2014

Biochemistry Research International

135

109

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Tyrosinase is a natural enzyme and is often purified to only a low degree and it is involved in a variety of functions which mainly catalyse the o-hydroxylation of monophenols into their corresponding o-diphenols and the oxidation of o-diphenols to o-quinones using molecular oxygen, which then polymerizes to form brown or black pigments. The synthesis of o-diphenols is a potentially valuable catalytic ability and thus tyrosinase has attracted a lot of attention with respect to industrial applications. In environmental technology it is used for the detoxification of phenol-containing wastewaters and contaminated soils, as biosensors for phenol monitoring, and for the production of L-DOPA in pharmaceutical industries, and is also used in cosmetic and food industries as important catalytic enzyme. Melanin pigment synthesized by tyrosinase has found applications for protection against radiation cation exchangers, drug carriers, antioxidants, antiviral agents, or immunogen. The recombinant V. spinosum tryosinase protein can be used to produce tailor-made melanin and other polyphenolic materials using various phenols and catechols as starting materials. This review compiles the recent data on biochemical and molecular properties of microbial tyrosinases, underlining their importance in the industrial use of these enzymes. After that, their most promising applications in pharmaceutical, food processing, and environmental fields are presented.

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Section: Introductionmentioning

confidence: 99%

Microbial Tyrosinases: Promising Enzymes for Pharmaceutical, Food Bioprocessing, and Environmental Industry

Zaidi

Ali²,

Ali³

et al. 2014

Biochemistry Research International

135

109

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“…Modification of dextranase with 1-ethyl-3-[3-(dimethylamino)-propyl]-carbodiimide and α-epoxyalkylα-glucosides caused inactivation of dextranase, indicating that carboxyl groups are essential for the enzyme action (15). High expression of tyrosinase to produce melanin in cancerous melanocytes can lead to an improvement in cancer, the same that can be controlled or treated by reducing or inhibiting the activity of tyrosinase (16). MT is a good model for such studies on structure-function relationship and also, it has a good potential for clinical, industrial, agricultural, and food studies.…”

Section: Introductionmentioning

confidence: 99%

Kinetic, Thermodynamic and Structural Studies of Native and N-Bromosuccinimide-Modified Mushroom Tyrosinase

Emami¹,

Gheibi

2016

Biotech Health Sci

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Background: Mushroom tyrosinase (MT) as a metalloenzyme is a good model for mechanistic studies of melanogenesis. To recognize the mechanism of MT action, it is important to investigate its inhibition, activation, mutation, and modification properties. Objectives: In this study, the chemical modification of MT tryptophan residues was carried out by using N-bromosuccinimide (NBS) and then, the activity, stability, and structure of the native and modified enzymes were compared. Methods: Chemical modification of MT tryptophan residues was accomplished by enzyme incubation with different concentrations of NBS. The relative activity of native and modified MT was investigated through catecholase enzyme reaction in presence of dihydroxyphenylalanine (L-Dopa) as substrate. Thermodynamic parameters including standard Gibbs free energy change (∆G25°C) and Melting temperature (Tm) were obtained from thermal denaturation of the native and modified enzymes. The circular dichroism and intrinsic fluorescence techniques were used to study secondary and tertiary structure of MT, respectively. All experiments were conducted in 2015 in biophysical laboratory of Qazvin University of Medical Sciences and Islamic Azad University, Science and Research Branch, Tehran. Results: The relative activity reduced from 100% for native enzyme to 10%, 7.9%, and 6.4% for modified MT with different NBS of

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“…In addition, tyrosinases are associated with wound healing, with the immune response in plants [9, 10]. In humans, tyrosinase is involved in the pigmentation in melanocytes [11–13], as a marker in melanoma patients [14] and as a target for the activation of prodrugs [15]. In the present work, as an initial step in evaluating the pharmaceutical potential of the tyrosinase of mushroom Agaricus bisporus , we undertook a preliminary characterization of the enzyme.…”

Section: Introductionmentioning

confidence: 99%

Purification and Characterization of Melanogenic Enzyme Tyrosinase from Button Mushroom

Zaidi

Ali²,

Ali³

2014

Enzyme Research

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Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme, tyrosinase, catalyzes the first and only rate-limiting steps in melanogenesis. Since the discovery of its melanogenic properties, tyrosinase has been in prime focus and microbial sources of the enzyme are sought. Agaricus bisporus widely known as the common edible mushroom, it's taking place in high amounts of proteins, enzyme, carbohydrates, fibers, and low fat contents are frequently cited in the literature in relation to their nutritional value. In the present study tyrosinase from Agaricus bisporus was purified by ammonium sulphate precipitation, dialysis followed by gel filtration chromatography on Sephadex G-100, and ion exchange chromatography on DEAE-Cellulose; the enzyme was purified, 16.36-fold to give 26.6% yield on total activity in the crude extract and final specific activity of 52.19 U/mg. The SDS-PAGE electrophoresis showed a migrating protein band molecular weight of 95 kDa. The purified tyrosinase was optimized and the results revealed that the optimum values are pH 7.0 and temperature 35°C. The highest activity was reported towards its natural substrate, L-DOPA, with an apparent Km value of 0.933 mM. This indicated that tyrosinase purified from Agaricus bisporus is a potential source for medical applications.

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Tyrosinase Activated Melanoma Prodrugs

Cited by 39 publications

References 0 publications

Microbial Tyrosinases: Promising Enzymes for Pharmaceutical, Food Bioprocessing, and Environmental Industry

Microbial Tyrosinases: Promising Enzymes for Pharmaceutical, Food Bioprocessing, and Environmental Industry

Kinetic, Thermodynamic and Structural Studies of Native and N-Bromosuccinimide-Modified Mushroom Tyrosinase

Purification and Characterization of Melanogenic Enzyme Tyrosinase from Button Mushroom

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