Biochemical properties of the major proteins from Rhodnius prolixus eggshell.
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.
Bouts
Denise M D
DM
Instituto de Bioquímica Médica, Programa de Biologia Molecular e Biotecnologia, Universidade Federal do Rio de Janeiro, 21941-902 Rio de Janeiro/RJ, Brazil.
Melo
Ana Claudia do Amaral
AC
Andrade
Adriana Lyn Hunter
AL
Silva-Neto
Mário A C
MA
Paiva-Silva
Gabriela de Oliveira
Gde O
Sorgine
Marcos Henrique Ferreira
MH
da Cunha Gomes
Lílian Soares
LS
Coelho
Heloísa S
HS
Furtado
Adriano Penha
AP
Aguiar
Eduardo C M
EC
de Medeiros
Luciano Neves
LN
Kurtenbach
Eleonora
E
Rozental
Sonia
S
Cunha-E-Silva
Narcisa Leal
NL
de Souza
Wanderley
W
Masuda
Hatisaburo
H
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
D000935:Antifungal Agents; D004527:Egg Proteins; D019476:Insect Proteins