A heme-binding aspartic proteinase from the eggs of the hard tick Boophilus microplus

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dc.contributor.authorSorgine, MHF
dc.contributor.authorLogullo, C.
dc.contributor.authorZingali, R. B.
dc.contributor.authorPaiva-Silva, G. O.
dc.contributor.authorJuliano, Luiz [UNIFESP]
dc.contributor.authorOliveira, P. L.
dc.contributor.institutionUniversidade Federal do Rio de Janeiro (UFRJ)
dc.contributor.institutionUniversidade Federal de São Paulo (UNIFESP)
dc.contributor.institutionUniversidade Federal Fluminense (UFF)
dc.date.accessioned2016-01-24T12:31:10Z
dc.date.available2016-01-24T12:31:10Z
dc.date.issued2000-09-15
dc.description.abstractAn aspartic proteinase that binds heme with a 1:1 stoichiometry was isolated and cloned from the eggs of the cattle tick Boophilus microplus. This proteinase, herein named THAP (tick heme-binding aspartic proteinase) showed pepstatin-sensitive hydrolytic activity against several peptide and protein substrates, Although hemoglobin was a good substrate for THAP, low proteolytic activity was observed against globin devoid of the heme prosthetic group. Hydrolysis of globin by THAP increased as increasing amounts of heme were added to globin, with maximum activation at a heme-to-globin 1:1 ratio. Further additions of heme to the reaction medium inhibited proteolysis, back to a level similar to that observed against globin alone. the addition of heme did not change THAP activity toward a synthetic peptide or against ribonuclease, a non-hemeprotein substrate. the major storage protein of tick eggs, vitellin (VT), the probable physiological substrate of THAP, is a hemeprotein. Hydrolysis of VT by THAP was also inhibited by the addition of heme to the incubation media. Taken together, our results suggest that THAP uses heme bound to VT as a docking site to increase specificity and regulate VT degradation according to heme availability.en
dc.description.affiliationUniv Fed Rio de Janeiro, Ctr Ciencias Saude, Inst Ciencias Biomed, Dept Bioquim Med, BR-21910590 Rio de Janeiro, Brazil
dc.description.affiliationUNIFESP, Escola Paulista Med, Dept Biofis, BR-04044020 São Paulo, Brazil
dc.description.affiliationUniv Fed Fluminense, Inst Biol, Dept Biol Celular & Mol, BR-24001970 Niteroi, RJ, Brazil
dc.description.affiliationUnifespUNIFESP, Escola Paulista Med, Dept Biofis, BR-04044020 São Paulo, Brazil
dc.description.sourceWeb of Science
dc.format.extent28659-28665
dc.identifierhttp://dx.doi.org/10.1074/jbc.M005675200
dc.identifier.citationJournal of Biological Chemistry. Bethesda: Amer Soc Biochemistry Molecular Biology Inc, v. 275, n. 37, p. 28659-28665, 2000.
dc.identifier.doi10.1074/jbc.M005675200
dc.identifier.issn0021-9258
dc.identifier.urihttp://repositorio.unifesp.br/handle/11600/26383
dc.identifier.wosWOS:000089330700044
dc.language.isoeng
dc.publisherAmer Soc Biochemistry Molecular Biology Inc
dc.relation.ispartofJournal of Biological Chemistry
dc.rightsinfo:eu-repo/semantics/openAccess
dc.titleA heme-binding aspartic proteinase from the eggs of the hard tick Boophilus microplusen
dc.typeinfo:eu-repo/semantics/article
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