title: Biochemical properties of the major proteins from Rhodnius prolixus eggshell.
abstract: Two proteins from the eggshell of Rhodnius prolixus were isolated, characterized and named Rp30 and Rp45 according to their molecular masses. Purified proteins were used to obtain specific antiserum which was later used for immunolocalization. The antiserum against Rp30 and Rp45 detected their presence inside the follicle cells, their secretion and their association with oocyte microvilli. Both proteins are expressed during the final stage of vitellogenesis, preserved during embryogenesis and discarded together with the eggshell. The amino terminals were sequenced and both proteins were further cloned using degenerated primers. The amino acid sequences appear to have a tripartite arrangement with a highly conserved central domain which presents a repetitive motif of valine-proline-valine (VPV) at intervals of 15 amino acid residues. Their amino acid sequence showed no similarity to any known eggshell protein. The expression of these proteins was also investigated; the results demonstrated that this occurred strictly in choriogenic follicles. Antifungal activity against Aspergillus niger was found to be associated with Rp45 but not with Rp30. A. niger exposed to Rp45 protein induced growth inhibition and several morphological changes such as large vacuoles, swollen mitochondria, multi-lamellar structures and a disorganized cell wall as demonstrated by electron microscopy analysis.
authors.affiliation: Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro/RJ, Brazil.
authors.forename: Denise M D
authors.initials: DM
authors.lastname: Bouts
authors.forename: Ana Claudia do Amaral
authors.initials: AC
authors.lastname: Melo
authors.forename: Adriana Lyn Hunter
authors.initials: AL
authors.lastname: Andrade
authors.forename: Mário A C
authors.initials: MA
authors.lastname: Silva-Neto
authors.forename: Gabriela de Oliveira
authors.initials: Gde O
authors.lastname: Paiva-Silva
authors.forename: Marcos Henrique Ferreira
authors.initials: MH
authors.lastname: Sorgine
authors.forename: Lílian Soares
authors.initials: LS
authors.lastname: da Cunha Gomes
authors.forename: Heloísa S
authors.initials: HS
authors.lastname: Coelho
authors.forename: Adriano Penha
authors.initials: AP
authors.lastname: Furtado
authors.forename: Eduardo C M
authors.initials: EC
authors.lastname: Aguiar
authors.forename: Luciano Neves
authors.initials: LN
authors.lastname: de Medeiros
authors.forename: Eleonora
authors.initials: E
authors.lastname: Kurtenbach
authors.forename: Sonia
authors.initials: S
authors.lastname: Rozental
authors.forename: Narcisa Leal
authors.initials: NL
authors.lastname: Cunha-E-Silva
authors.forename: Wanderley
authors.initials: W
authors.lastname: de Souza
authors.forename: Hatisaburo
authors.initials: H
authors.lastname: Masuda
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D001234:Aspergillus niger / Q000187:drug effects; D003001:Cloning, Molecular; D004527:Egg Proteins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D047108:Embryonic Development; D019476:Insect Proteins / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010063:Ovum / Q000378:metabolism; D012239:Rhodnius / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein; D014818:Vitellogenesis
chemical_list: D000935:Antifungal Agents; D004527:Egg Proteins; D019476:Insect Proteins