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1391/12/22، جلد ۸، شماره ۱، صفحات -
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| عنوان فارسی |
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| چکیده فارسی مقاله |
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| عنوان انگلیسی |
Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing Enzymes |
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| چکیده انگلیسی مقاله |
ABSTRACT Background: Like several other parasites, Teladorsagia circumcincta secretes or excretes urea, but neither the rate of efflux nor the possible metabolic sources of the urea has been considered. Methods: Parasites were maintained by passage through sheep. Urea efflux was measured using phenol/hypochlorite after treatment with urea aminohydrolase. The kinetics of creatine amidinohydrolase and arginine amidinohydrolase were characterised by coupling the reactions with urea aminohydrolase and glutamate dehydrogenase. Results: Infective L 3 T. circumcincta secreted or excreted urea at 25% of the rate of NH 3 /NH 4 + . The rate of urea efflux was about 84 pmol h ‑1 (10 3 larvae) ‑1 over 4 hours, corresponding to about 11 nmol h -1 mg -1 protein. We could not detect urea aminohydrolase activity, but urea production by both creatine amidinohydrolase and arginine amidinohydrolase could be detected. The apparent K m and V max of creatine amidinohydrolase were 1.1 mM and 48 nmol h -1 mg -1 protein, respectively, and the activity was greatest at pH 8. The apparent K m and V max of arginine amidinohydrolase were 0.7 mM and 62 nmol h -1 mg -1 protein, respectively, and the activity was greatest at pH 7.9. Conclusion: The activity of creatine amidinohydrolase and arginine amidinohydrolase was sufficient to account for the rate of urea secretion or excretion. Keywords: Kinetics, Teladorsagia circumcincta , Urea |
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| کلیدواژه‌های انگلیسی مقاله |
Keywords: Kinetics, Teladorsagia circumcincta , Urea |
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| نویسندگان مقاله |
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| نشانی اینترنتی |
http://ijpa.tums.ac.ir/index.php/ijpa/article/viewArticle/556 |
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| زبان مقاله منتشر شده |
en |
| موضوعات مقاله منتشر شده |
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| نوع مقاله منتشر شده |
Articles |
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