Antioxidant role of Rhodnius prolixus heme-binding protein. Protection against heme-induced lipid peroxidation.
J Biol Chem
; 270(18): 10893-6, 1995 May 05.
Article
em En
| MEDLINE
| ID: mdl-7738029
ABSTRACT
Heme in aqueous solutions actively promotes free radical reactions leading to degradation of biological molecules. The blood-sucking insect Rhodnius prolixus has a heme-binding protein (RHBP) in its hemolymph (Oliveira, P.L., Kawooya, J.K., Ribeiro, J.M.C., Meyer, T., Poorman, R., Alves, E.W., Walker, F., Padovan, G.J., and Masuda, H. (1994) J. Biol. Chem. 270, 10897-10901. Here we show that this protein inhibits heme-dependent peroxidation of both linolenic acid liposomes and lipophorin, the main lipoprotein of insect hemolymph. The oxidized lipophorin is functionally impaired, being defective both in its capacity to be loaded with phospholipids from the fat body as well as in its ability to deliver phospholipids to the growing oocytes. RHBP prevents the heme-induced oxidative damage to lipophorin. It is proposed that in vivo RHBP binds the heme derived from digestion of blood hemoglobin, suppressing the generation of activated oxygen species and protecting the insect against oxidative stress throughout the feeding cycle.
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Base de dados:
MEDLINE
Assunto principal:
Rhodnius
/
Proteínas de Transporte
/
Hemeproteínas
/
Peróxidos Lipídicos
/
Lipoproteínas
Idioma:
En
Ano de publicação:
1995
Tipo de documento:
Article