|کد مقاله||کد نشریه||سال انتشار||مقاله انگلیسی||ترجمه فارسی||نسخه تمام متن|
|4753443||1416558||2017||5 صفحه PDF||سفارش دهید||دانلود رایگان|
A Î²-d-galactosidase exhibiting high activity in the alkaline pH region was purified from Teratosphaeria acidotherma AIU BGA-1, which we previously isolated as a unique fungal producer of three acidophilic and one alkalophilic Î²-d-galactosidases (Isobe etÂ al., J. Biosci. Bioeng., 116, 171-174, 2013). The enzyme was stable in the pH range 7.5-10.0 and exhibited optimal activity at pH 8.0 and 60Â°C. The enzyme hydrolyzed 2-nitrophenyl Î²-d-galactopyranoside, 4-nitrophenyl Î²-d-galactopyranoside, and lactose, and the Km values were estimated to be 0.349Â mM, 0.488Â mM, and 701Â mM, respectively. Chelating reagents (EDTA and o-phenanthroline) and metals (Cu2+and Ni2+) inhibited the enzyme activity, and Mn2+ was a good activator. The enzyme also exhibited transgalactosylation activity for lactose. The enzyme's molecular mass was estimated to be 180Â kDa, and its structure was monomeric. Thus, the enzymatic and physicochemical characteristics of the alkalophilic Î²-galactosidase in this study clearly differed from those of the previously known alkalophilic Î²-d-galactosidases.
Journal: Journal of Bioscience and Bioengineering - Volume 123, Issue 1, January 2017, Pages 15-19