Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing Enzymes
Background: Like several other parasites, Teladorsagia circumcincta secretes or excretes urea, but nei-ther 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 phe-nol/hy...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Tehran University of Medical Sciences
2013-03-01
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| Series: | Iranian Journal of Parasitology |
| Subjects: | |
| Online Access: | https://ijpa.tums.ac.ir/index.php/ijpa/article/view/515 |
| _version_ | 1818403176551809024 |
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| author | N Muhamad Lr Walker Dc Simcock Kc Pedley Hv Simpson S Brown |
| author_facet | N Muhamad Lr Walker Dc Simcock Kc Pedley Hv Simpson S Brown |
| author_sort | N Muhamad |
| collection | DOAJ |
| description | Background: Like several other parasites, Teladorsagia circumcincta secretes or excretes urea, but nei-ther 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 phe-nol/hypochlorite after treatment with urea aminohydrolase. The kinetics of creatine amidinohy-drolase and arginine amidinohydrolase were characterised by coupling the reactions with urea ami-nohydrolase and glutamate dehydrogenase.
Results: Infective L3 T. circumcincta secreted or excreted urea at 25% of the rate of NH3/NH4+. The rate of urea efflux was about 84 pmol h-1 (103 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 Km and Vmax 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 Km and Vmax 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. |
| first_indexed | 2024-12-14T08:20:06Z |
| format | Article |
| id | doaj.art-f4e7b38c64f6449d9f52289b8970d344 |
| institution | Directory Open Access Journal |
| issn | 1735-7020 2008-238X |
| language | English |
| last_indexed | 2024-12-14T08:20:06Z |
| publishDate | 2013-03-01 |
| publisher | Tehran University of Medical Sciences |
| record_format | Article |
| series | Iranian Journal of Parasitology |
| spelling | doaj.art-f4e7b38c64f6449d9f52289b8970d3442022-12-21T23:09:50ZengTehran University of Medical SciencesIranian Journal of Parasitology1735-70202008-238X2013-03-0181Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing EnzymesN Muhamad0Lr Walker1Dc Simcock2Kc Pedley3Hv Simpson4S Brown5Universiti Kuala Lumpur, Royal College of Medicine Perak, 3 Greentown Road, 30450 Ipoh, Perak, Malaysia.Institute of Food, Nutrition and Human Health, Massey University, Private Bag, Palmerston North, New Zealand.Institute of Food, Nutrition and Human Health, Massey University, Private Bag, Palmerston North, New Zealand.Institute of Food, Nutrition and Human Health, Massey University, Private Bag, Palmerston North, New Zealand.Institute of Veterinary and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North, New Zealand.School of Human Life Sciences, University of Tasmania, Locked Bag 1320, Launceston, Tasmania 7250, Australia.Background: Like several other parasites, Teladorsagia circumcincta secretes or excretes urea, but nei-ther 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 phe-nol/hypochlorite after treatment with urea aminohydrolase. The kinetics of creatine amidinohy-drolase and arginine amidinohydrolase were characterised by coupling the reactions with urea ami-nohydrolase and glutamate dehydrogenase. Results: Infective L3 T. circumcincta secreted or excreted urea at 25% of the rate of NH3/NH4+. The rate of urea efflux was about 84 pmol h-1 (103 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 Km and Vmax 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 Km and Vmax 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.https://ijpa.tums.ac.ir/index.php/ijpa/article/view/515KineticsTeladorsagia circumcinctaUrea |
| spellingShingle | N Muhamad Lr Walker Dc Simcock Kc Pedley Hv Simpson S Brown Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing Enzymes Iranian Journal of Parasitology Kinetics Teladorsagia circumcincta Urea |
| title | Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing Enzymes |
| title_full | Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing Enzymes |
| title_fullStr | Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing Enzymes |
| title_full_unstemmed | Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing Enzymes |
| title_short | Urea Output by L3 Teladorsagia circumcincta and some Properties of Two Urea Producing Enzymes |
| title_sort | urea output by l3 teladorsagia circumcincta and some properties of two urea producing enzymes |
| topic | Kinetics Teladorsagia circumcincta Urea |
| url | https://ijpa.tums.ac.ir/index.php/ijpa/article/view/515 |
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