Prolyl oligopeptidase of Trypanosoma brucei hydrolyzes native collagen, peptide hormones and is active in the plasma of infected mice.
Proteases play important roles in many biological processes of parasites, including their host interactions. In sleeping sickness, Trypanosoma brucei proteases released into the host bloodstream could hydrolyze host factors, such as hormones, contributing to the development of the disease's symptoms. In this study, we present the identification of the T. brucei prolyl oligopeptidase gene (poptb) and the characterization of its corresponding enzyme, POP Tb. Secondary structure predictions of POP Tb show a structural composition highly similar to other POPs. Recombinant POP Tb produced in E. coli was active and highly sensitive to inhibitors of Trypanosoma cruzi POP Tc80. These inhibitors, which prevent T. cruzi entry into non-phagocytic cells, arrested growth of the T. brucei bloodstream form in a dose-dependent manner. POP Tb hydrolyzes peptide hormones containing Pro or Ala at the P1 position at a slightly alkaline pH, and also cleaves type I collagen in vitro and native collagen present in rat mesentery. Furthermore, POP Tb is released into the bloodstream of T. brucei infected mice where it remains active. These data suggest that POP Tb might contribute to the pathogenesis of sleeping sickness.
Bastos
Izabela M D
IM
Laboratório de Interação Parasito-Hospedeiro, Faculdade de Medicina, Universidade de Brasília, 70910-900-DF, Brazil. dourado@unb.br
Motta
Flávia Nader
FN
Charneau
Sébastien
S
Santana
Jaime M
JM
Dubost
Lionel
L
Augustyns
Koen
K
Grellier
Philippe
P
D000818:Animals; D003094:Collagen / Q000378:metabolism*; D017124:Conserved Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D006790:Host-Parasite Interactions; D006801:Humans; D051379:Mice; D036361:Peptide Hormones / Q000378:metabolism*; D000085822:Prolyl Oligopeptidases; D011480:Protease Inhibitors / Q000494:pharmacology; D015800:Protozoan Proteins; D051381:Rats; D012697:Serine Endopeptidases / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D014353:Trypanosomiasis, African / Q000097:blood / Q000201:enzymology
D036361:Peptide Hormones; D011480:Protease Inhibitors; D015800:Protozoan Proteins; D003094:Collagen; D012697:Serine Endopeptidases; C000705287:PREPL protein, human; D000085822:Prolyl Oligopeptidases; C000705288:Tc80 prolyl oligopeptidase, Trypanosoma cruzi