title: Amino acid catabolism in the nematodes Heligmosomoides polygyrus and Panagrellus redivivus. 1. Removal of the amino group.
abstract: The major transaminase in Heligmosomoides polygyrus, Panagrellus redivivus and rat liver was the 2-oxoglutarate-glutamate system, with relatively few amino acids acting as donors for the pyruvate-alanine and oxaloacetate-aspartate systems. The relative effectiveness of the different amino acid donors in the three transaminase systems was similar in all three tissues. Both H. polygyrus and P. redivivus can oxidatively deaminate a range of L-amino acids, although D-amino acid oxidase activity was low. Serine and threonine dehydratase activity and histidase activity were present in H. polygyrus and P. redivivus and both nematodes were also able to deaminate glutamine, asparagine and arginine. When NAD(H) was the cofactor the glutamate dehydrogenases of H. polygyrus and P. redivivus showed similar regulatory properties to the mammalian enzyme. However, with NADP(H) the results were anomalous. The capacity of both nematodes to transaminate and oxidatively deaminate amino acids was broadly similar and comparable to mammalian tissue. Glutamate dehydrogenase is probably the major route for deamination in these nematodes. A complete sequence of urea cycle enzymes could not be demonstrated in either P. redivivus or H. polygyrus.
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D006369:Heligmosomatoidea / Q000201:enzymology*; D008099:Liver / Q000201:enzymology; D008297:Male; D051379:Mice; D009348:Nematoda / Q000201:enzymology*; D009351:Nematospiroides dubius / Q000201:enzymology*; D051381:Rats; D000637:Transaminases / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D000637:Transaminases