Enzymes of the ornithine-glutamate-proline pathway in the sheep abomasal nematode parasites Haemonchus contortus and Teladorsagia circumcincta

► A functional ornithine-glutamate-proline pathway was present in abomasal nematodes. ► Activity was detected for OAT, P5CDH, P5CS, P5CR and proline oxidase. ► Substrate affinity was generally similar for each species and life cycle stage. ► The exception was the 10-fold lower affinity for P5C of adult Teladorsagia circumcincta P5CR.