Limits...
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.


Lineweaver-Burk plot of A. bisporus tyrosinase. Data were obtained as mean value of 1/[V], inverse of the increase of optical density at 475 nm per min (OD475), of three independent tests with different concentrations of L-DOPA as a substrate.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC4150416&req=5

fig6: Lineweaver-Burk plot of A. bisporus tyrosinase. Data were obtained as mean value of 1/[V], inverse of the increase of optical density at 475 nm per min (OD475), of three independent tests with different concentrations of L-DOPA as a substrate.

Mentions: The Km value of tyrosinase was found to be 0.933 mM shown in (Figure 6). This result indicates the high affinity of tyrosinase towards its substrate, which might relate to its degree of effectiveness against melanogenesis. Higher Km values 0.9 and 0.85 mM for tyrosinase from Pycnoporus sanguineus and Lentinula edodes, respectively, have been reported [24, 29]. On The other hand, a lower Km value (0.075 mM) was obtained for tyrosinase from Bacillus megaterium [31].


Purification and characterization of melanogenic enzyme tyrosinase from button mushroom.

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

Lineweaver-Burk plot of A. bisporus tyrosinase. Data were obtained as mean value of 1/[V], inverse of the increase of optical density at 475 nm per min (OD475), of three independent tests with different concentrations of L-DOPA as a substrate.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig6: Lineweaver-Burk plot of A. bisporus tyrosinase. Data were obtained as mean value of 1/[V], inverse of the increase of optical density at 475 nm per min (OD475), of three independent tests with different concentrations of L-DOPA as a substrate.
Mentions: The Km value of tyrosinase was found to be 0.933 mM shown in (Figure 6). This result indicates the high affinity of tyrosinase towards its substrate, which might relate to its degree of effectiveness against melanogenesis. Higher Km values 0.9 and 0.85 mM for tyrosinase from Pycnoporus sanguineus and Lentinula edodes, respectively, have been reported [24, 29]. On The other hand, a lower Km value (0.075 mM) was obtained for tyrosinase from Bacillus megaterium [31].

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.