Triatoma infestans apyrases belong to the 5'-nucleotidase family.
Apyrases are nucleoside triphosphate-diphosphohydrolases (EC 3.6.1.5) present in a variety of organisms. The apyrase activity found in the saliva of hematophagous insects is correlated with the prevention of ADP-induced platelet aggregation of the host during blood sucking. Purification of apyrase activity from the saliva of the triatomine bug Triatoma infestans was achieved by affinity chromatography on oligo(dT)-cellulose and gel filtration chromatography. The isolated fraction includes five N-glycosylated polypeptides of 88, 82, 79, 68 and 67 kDa apparent molecular masses. The isolated apyrase mixture completely inhibited aggregation of human blood platelets. Labeling with the ATP substrate analogue 5'-p-fluorosulfonylbenzoyladenosine showed that the five species have ATP-binding characteristic of functional apyrases. Furthermore, tandem mass spectroscopy peptide sequencing showed that the five species share sequence similarities with the apyrase from Aedes aegypti and with 5'-nucleotidases from other species. The complete cDNA of the 79-kDa enzyme was cloned, and its sequence confirmed that it encodes for an apyrase belonging to the 5'-nucleotidase family. The gene multiplication leading to the unusual salivary apyrase diversity in T. infestans could represent an important mechanism amplifying the enzyme expression during the insect evolution to hematophagy, in addition to an escape from the host immune response, thus enhancing acquisition of a meal by this triatomine vector of Chagas' disease.
Chagas' Disease Multidisciplinary Research Laboratory, Department of Pathology, Faculty of Medicine, University of Brasília, Brazil 70.910-900.
Eric
E
Faudry
Silene P
SP
Lozzi
Jaime M
JM
Santana
Marian
M
D'Souza-Ault
Sylvie
S
Kieffer
Carlos R
CR
Felix
Carlos A O
CA
Ricart
Marcelo V
MV
Sousa
Thierry
T
Vernet
Antonio R L
AR
Teixeira
D015720:5'-Nucleotidase / Q000737:chemistry*; D000241:Adenosine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000244:Adenosine Diphosphate / Q000737:chemistry; D000255:Adenosine Triphosphate / Q000737:chemistry; D000345:Affinity Labels / Q000494:pharmacology; D000595:Amino Acid Sequence; D000818:Animals; D001081:Apyrase / Q000737:chemistry*; D005075:Biological Evolution; D001792:Blood Platelets / Q000378:metabolism; D015139:Blotting, Southern; D015153:Blotting, Western; D002460:Cell Line; D002845:Chromatography; D002850:Chromatography, Gel; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D015723:Gene Library; D006031:Glycosylation; D006801:Humans; D007313:Insecta; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D010974:Platelet Aggregation; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000737:chemistry; D012463:Saliva / Q000201:enzymology; D017386:Sequence Homology, Amino Acid; D014224:Triatoma / Q000201:enzymology*; D014349:Trypanosoma cruzi / Q000382:microbiology
D000345:Affinity Labels; D018076:DNA, Complementary; D010455:Peptides; D011994:Recombinant Proteins; D000244:Adenosine Diphosphate; C010959:5'-(4-fluorosulfonylbenzoyl)adenosine; D000255:Adenosine Triphosphate; D015720:5'-Nucleotidase; D001081:Apyrase; D000241:Adenosine