Salivary apyrases of Triatoma infestans are assembled into homo-oligomers.
Apyrase activity is present in the saliva of haematophagous arthropods. It is related to blood-feeding because of the apyrase ability to hydrolyse ADP, a key component of platelet aggregation. Five apyrases with apparent molecular masses of 88, 82, 79, 68 and 67 kDa were identified in the saliva of the vector of Chagas disease, Triatoma infestans. The large size observed during purification of these enzymes suggested oligomerization. In the present study, we confirmed, using gel-filtration and analytical ultracentrifugation, the presence of apyrase oligomers with molecular masses of 200 kDa in the saliva. Electrophoretic analyses showed that disulphide bonds were involved in homo-oligomerization. In addition, heterogeneity in disulphide bonds and in pI was detected, with the pI ranging from 4.9 to 5.4. The present study gives the first insights into the quaternary structure of soluble apyrases.
Chagas Disease Multidisciplinary Research Laboratory, Faculty of Medicine, University of Brasilia, Brazil 70.910-900.
Eric
E
Faudry
Jaime M
JM
Santana
Christine
C
Ebel
Thierry
T
Vernet
Antonio R L
AR
Teixeira
D000818:Animals; D001081:Apyrase / Q000096:biosynthesis* / Q000302:isolation & purification; D002850:Chromatography, Gel; D003432:Cross-Linking Reagents / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D004229:Dithiothreitol / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D020836:Protein Structure, Quaternary; D012463:Saliva / Q000201:enzymology; D013388:Succinimides / Q000737:chemistry; D014224:Triatoma / Q000201:enzymology*; D014461:Ultracentrifugation
D003432:Cross-Linking Reagents; D004220:Disulfides; D013388:Succinimides; C035759:3,3'-dithiobis(sulfosuccinimidyl propionate); D001081:Apyrase; D004229:Dithiothreitol