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Purification and characterization of melanogenic enzyme tyrosinase from button mushroom.

Zaidi KU, Ali AS, Ali SA - Enzyme Res (2014)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biotechnology Laboratory, Centre for Scientific Research & Development, People's University, Bhopal 462010, India.

ABSTRACT
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.

No MeSH data available.


Effect of temperature on the tyrosinase activity of the crude extract prepared from A. bisporus. Data were obtained as mean value of optical density. Assays were done in potassium phosphate buffer (100 mM, pH = 7.0). The optimum activity of the sample incubated at 35°C was taken as 100%.
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fig4: Effect of temperature on the tyrosinase activity of the crude extract prepared from A. bisporus. Data were obtained as mean value of optical density. Assays were done in potassium phosphate buffer (100 mM, pH = 7.0). The optimum activity of the sample incubated at 35°C was taken as 100%.

Mentions: The purified tyrosinase was active at a wide range of temperature from 30°C to 65°C with an optimum at 35°C (Figure 4), and about 35% of tyrosinase activity was still present at 55°C, but it lost its activity at 65°C. Our results were in agreement with a previous study which reported that the optimum temperature for tyrosinase activity obtained from Streptomyces sp. was 35°C. Tyrosinase from Pseudomonas putida and Trichoderma reesei showed maximum activity at 30°C [27, 30], and maximum activity of tyrosinase purified from Bacillus megaterium and Lentinula boryana was at 40°C [31, 32].


Purification and characterization of melanogenic enzyme tyrosinase from button mushroom.

Zaidi KU, Ali AS, Ali SA - Enzyme Res (2014)

Effect of temperature on the tyrosinase activity of the crude extract prepared from A. bisporus. Data were obtained as mean value of optical density. Assays were done in potassium phosphate buffer (100 mM, pH = 7.0). The optimum activity of the sample incubated at 35°C was taken as 100%.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4150416&req=5

fig4: Effect of temperature on the tyrosinase activity of the crude extract prepared from A. bisporus. Data were obtained as mean value of optical density. Assays were done in potassium phosphate buffer (100 mM, pH = 7.0). The optimum activity of the sample incubated at 35°C was taken as 100%.
Mentions: The purified tyrosinase was active at a wide range of temperature from 30°C to 65°C with an optimum at 35°C (Figure 4), and about 35% of tyrosinase activity was still present at 55°C, but it lost its activity at 65°C. Our results were in agreement with a previous study which reported that the optimum temperature for tyrosinase activity obtained from Streptomyces sp. was 35°C. Tyrosinase from Pseudomonas putida and Trichoderma reesei showed maximum activity at 30°C [27, 30], and maximum activity of tyrosinase purified from Bacillus megaterium and Lentinula boryana was at 40°C [31, 32].

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Molecular Biotechnology Laboratory, Centre for Scientific Research & Development, People's University, Bhopal 462010, India.

ABSTRACT
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.

No MeSH data available.