RESUMO
Studies were carried out to determine the effect of rat liver cytosolic protein enriched in fatty acid binding protein on the microsomal and mitochondrial ascorbate-Fe+2 lipid peroxidation and to determine how vitamin A influences the inhibitory effect of this protein in the peroxidation process. The inhibition of light emission (maximal induced chemiluminescence) by the fatty acid binding protein containing fraction was protein concentration dependent. The inhibition of chemiluminescence produced by the addition of cytosolic protein on rat liver microsomes or mitochondria was more evident when the soluble protein obtained from the vitamin A treated group was used. The results indicated that vitamin A plays a role in protecting rat liver microsomes and mitochondria against the harmful effect of lipid peroxidation.
Assuntos
Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/química , Microssomos Hepáticos/metabolismo , Mitocôndrias Hepáticas/metabolismo , Proteínas de Neoplasias , Proteínas do Tecido Nervoso , Proteínas/farmacologia , Vitamina A/farmacologia , Animais , Proteínas de Transporte/análise , Proteínas de Transporte/farmacologia , Citosol/química , Proteína 7 de Ligação a Ácidos Graxos , Proteínas de Ligação a Ácido Graxo , Medições Luminescentes , Microssomos Hepáticos/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Proteína P2 de Mielina/análise , Proteína P2 de Mielina/farmacologia , Proteínas/análise , RatosRESUMO
Five fatty-acid-binding proteins from the liver of the elephant fish (Callorhynchus callorhynchus), a chimaera fish that belongs--together with the elasmobranchs--to the ancient chondrichthyes class were isolated and characterized. The purification procedures for these proteins involved gel filtration, anion-exchange chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a last step. They were submitted to "in gel" tryptic or cyanogen bromide digestion and the resulting peptides were separated by high performance liquid chromatography and then sequenced by Edman degradation. According to their partial amino acid sequences, one of them presents the highest identity with fatty-acid-binding proteins from human and catfish liver, another three with those from mammalian heart or adipose tissue and the fifth with the mammalian intestinal fatty-acid-binding protein. The presence of various members of this protein family, as now found in elephant fish and previously in catfish (Rhamdia sapo) liver, does not occur in mammalian liver which express only one a characteristic fatty-acid-binding protein.