کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
18196 42713 2007 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Biochemical characterisation of the coexisting tyrosinase and laccase in the soil bacterium Pseudomonas putida F6
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
پیش نمایش صفحه اول مقاله
Biochemical characterisation of the coexisting tyrosinase and laccase in the soil bacterium Pseudomonas putida F6
چکیده انگلیسی

Two phenol oxidases, a tyrosinase and a laccase were isolated from cell extracts of the soil bacterium Pseudomonas putida F6. Both oxidases were purified to homogeneity separately using a combination of anion exchange chromatography, gel filtration and gel slicing. The purified tyrosinase is a monomer with a relative molecular mass (Mr) of approximately 39,000 while the purified laccase has a relative molecular mass (Mr) of approximately 59,000. Maximum activity, for tyrosinase with l-tyrosine (monophenolase) and l-dopa (diphenolase) and for laccase with syringaldazine, was observed at 30 °C and pH 7.0. Both enzymes were stable over a broad range of temperatures and were most stable at 30 °C. Both the monophenolase and diphenolase activities of tyrosinase were relatively stable across a broad range of pH values with maximum stability at pH 5.0 and 4.0, respectively. Laccase was most stable at pH 7.0 with a narrow bell shaped curve over a range of pH values. P. putida F6 tyrosinase has a 1.5-fold higher affinity for l-tyrosine compared to l-dopa. Furthermore P. putida F6 tyrosinase exhibits a 2.7-fold higher affinity for α-methyl-dl-tyrosine compared to α-methyl-l-tyrosine.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Enzyme and Microbial Technology - Volume 40, Issue 5, 3 April 2007, Pages 1435–1441
نویسندگان
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