Phosphoenolpyruvate metabolism in Teladorsagia circumcincta: A critical junction between aerobic and anaerobic metabolism |
| |
| Authors: | DC Simcock LR Walker KC Pedley HV Simpson S Brown |
| |
| Institution: | 1. Institute of Food Nutrition and Human Health, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand;2. Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand;3. School of Human Life Sciences, University of Tasmania, Locked Bag 1320, Launceston, Tasmania 7250, Australia;1. Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7;2. Department of Chemistry, The University of Western Ontario, London, Ontario, Canada N6A 5B7;1. Department of Neurosurgery, La Princesa University Hospital, Madrid, Spain;2. Department of Neurosurgery, Virgen de La Salud Hospital, Toledo, Spain;3. Department of Endocrinology, Hospital del Sureste, Madrid, Spain;4. Department of Neurosurgery, Ramón y Cajal University Hospital, Madrid, Spain;1. Department of Haematology, Heart of England NHS Foundation Trust, Birmingham, UK;2. Department of Haematology, Bristol Royal Infirmary, Bristol, UK;3. Centre for Clinical Haematology, Queen Elizabeth Hospital Birmingham, Birmingham, UK;4. Cancer Studies Institute, University of Birmingham, Birmingham, UK;5. Department of Haematology University Hospital NHS Trust Dundee, Dundee, UK;6. West Midlands Regional Genetics Laboratory, Birmingham Women''s Hospital, Birmingham, UK;1. Service d’explorations fonctionnelles pédiatriques, Hôpital d’Enfants, CHU de Nancy, France;2. EA 3450, Laboratoire de Physiologie, Faculté de Médecine, Université de Lorraine, France |
| |
| Abstract: | Nematodes which have adapted to an anaerobic lifestyle in their adult stages oxidise phosphoenolpyruvate (PEP) to oxaloacetate rather than pyruvate as the final product of glycolysis. This adaptation involves selective expression of the enzyme phosphoenolpyruvate carboxykinase (PEPCK), instead of pyruvate kinase (PK). However, such adaptation is not absolute in aerobic nematode species. We have examined the activity and kinetics of PEPCK and PK in larvae (L3) and adults of Teladorsagia circumcincta, a parasite known to exhibit oxygen uptake. Results revealed that PK and PEPCK activity existed in both L3s and adults. The enzymes had differing affinity for nucleotide diphosphates: while both can utilise GDP, only PK utilised ADP and only PEPCK utilised IDP. In both life cycle stages, enzymes showed similar affinity for PEP. PK activity was predominant in both stages, although activity of this enzyme was lower in adults. When combined, both the activity levels and the enzyme kinetics showed that pyruvate production is probably favoured in both L3 and adult stages of T. circumcincta and suggest that metabolism of PEP to oxaloacetate is a minor metabolic pathway in this species. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
