A comparison of the enzymatic properties of the major cysteine proteinases from Trypanosoma congolense and Trypanosoma cruzi

Chagas J.R., Authié Edith, Serveau Carole, Lalmanach Gilles, Juliano L., Gauthier Francis. 1997. A comparison of the enzymatic properties of the major cysteine proteinases from Trypanosoma congolense and Trypanosoma cruzi. Molecular and Biochemical Parasitology, 88 : 85-94.

Autre titre : Comparaison des propriétés enzymatiques des cystéines protéinases majeures de Trypanosoma congolense et Trypanosoma cruzi

Résumé : Congopain and cruzipain, the major cysteine proteinases from Trypanosoma congolense and Trypanosoma cruzi, were compared for their activities towards a series of new, sensitive fluorogenic substrates of the papain family of cysteine proteinases and for their sensitivity to inhibition by cystatins and related biotinylated peptidyl diazomethanes. Low Ki values, in the 10 pM range, were found for the interaction of both proteinases with natural cystatin inhibitors. The kinetic constants for the hydrolysis of cystatin-derived substrates, and the inhibition by related diazomethanes were essentially identical. Unlike cathepsins B and L, the related mammal papain family proteinases, congopain and cruzipain accomodate a prolyl residue in PT. Substrates having the sequence VGGP from P2 to PT were hydrolysed by both congopain and cruzipain with a kcat/K_ greater than 4.101 mM- 1 s-'. Irreversible diazomethane inhibitors, deduced from the unprime sequence of cystatin-derived substrates, inhibited the two parasite proteinases. N-terminal labelling of diazomethanes with a biotin group did not alter the rate of inhibition significantly, which provides a useful tool for examining the distribution of these enzymes in the parasite and in the host. Despite their similar activities on cystatin-derived substrates, congopain and cruzipain had significantly different pH-activity profiles when assayed with a cystatin-derived substrate. They were correlated with structural differences, especially at the presumed S2 subsites.

Mots-clés Agrovoc : Trypanosoma congolense, Trypanosoma brucei, protéase, cystéine, activité enzymatique

Classification Agris : L73 - Maladies des animaux

Auteurs et affiliations

• Chagas J.R.
• Authié Edith, CIRAD-EMVT-ELEVAGE-AGRICULTURE (KEN)
• Serveau Carole
• Lalmanach Gilles
• Juliano L.
• Gauthier Francis

Source : Cirad - Agritrop (https://agritrop.cirad.fr/401291/)

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