کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2470250 1555724 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Characterization of an ecto-5′-nucleotidase activity present on the cell surface of Tritrichomonas foetus
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم دامی و جانورشناسی
پیش نمایش صفحه اول مقاله
Characterization of an ecto-5′-nucleotidase activity present on the cell surface of Tritrichomonas foetus
چکیده انگلیسی

Tritrichomonas foetus is the causative agent of sexually transmitted trichomoniasis in cattle. In females, the infection can be associated with infertility, vaginitis, endometritis, abortion or pyometra, leading to significant economic losses in cattle raising. T. foetus is devoid of the ability to synthesize purine nucleotides de novo, depending instead on salvaging purines from the host environment. Ecto-5′-nucleotidase catalyzes the final step of extracellular nucleotide degradation, the hydrolysis of nucleoside 5′-monophosphates to the corresponding nucleosides and Pi. In this work we show that living, intact cells of T. foetus were able to hydrolyze 5′AMP at a rate of 12.57 ± 1.23 nmol Pi × h−1 × 10−7 cells at pH 7.2 and the 5′AMP hydrolysis is due to a plasma membrane-bound ecto-enzyme activity. The apparent Km for 5′AMP was 0.49 ± 0.06 mM. In addition to 5′AMP, the enzyme hydrolyzed all substrate monophosphates tested except 3′AMP. No divalent metals or metal chelators were able to modulate enzyme activity. Phosphatase inhibitors did not have an effect on ecto-5′-nucleotidase activity while ammonium molybdate did inhibit the activity in a dose dependent manner. The presence of adenosine in the culture medium negatively modulated the enzyme. These results indicate the existence of an ecto-5′-nucleotidase that may play a role in the salvage of purines.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Veterinary Parasitology - Volume 179, Issues 1–3, 30 June 2011, Pages 50–56
نویسندگان
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