ABSTRACT
Bioiron _ central to respiration, photosynthesis and DNA synthesis and complicated by radical chemistry with oxygen _ depends on ferritin, the super family of protein nanocages (maxi-ferritins in humans, animals, plants and bacteria, and mini-ferritins, also called DPS proteins, in bacteria) for iron and oxygen control. Regulation of ferritin synthesis, best studied in animals, uses DNA transcription and mRNA translation check points. Ferritin is a member of both the "oxidant stress response" gene family that includes thioredoxin reductase and quinine reductase, and a member of the iron responsive gene family that includes ferroportin and mt-aconitase ferritin DNA regulation responds preferentially to oxidant response inducers and ferritin mRNA to iron inducers; heme confers regulator synergy. Ferritin proteins manage iron and oxygen, with ferroxidase sites and iron + oxygen substrates to form mineral of both Fe and O atoms; maxi-ferritins contribute more to cellular iron metabolism and mini-ferritins to stress responses. Iron recovery from ferritin is controlled by gated protein pores, possibly contributing to iron absorption from ferritin, a significant dietary iron source. Ferritin gene regulation is a model for integrating DNA/mRNA controls, while ferritin protein function is central to molecular nutrition cellular metabolism at the crossroads of iron and oxygen in biology.
Subject(s)
Animals , Humans , Ferritins/biosynthesis , Homeostasis , Iron-Regulatory Proteins/metabolism , Iron/metabolism , Oxygen/metabolism , DNA , Gene Expression Regulation , Iron-Regulatory Proteins/genetics , RNA, Messenger/metabolism , Transcription, GeneticABSTRACT
En la presente investigacion se extrae, purifica y caracteriza una proteina almacenadora de hierro, la ferritina a partir de un homogenado de higado de vaca. Inicialmente la purificacion por desnaturacion termal y precipitacion con sulfato de amonio y posteriormente por metodos cromatograficos. En la segunda parte del estudio, se realiza un tratmiento comparativo en niños con anemia ferropenica con sulfato ferroso y con ferritina. El analisis estadistico del estudio refleja claramente respuesta significativa en el aumento de los niveles sericos de hierro en grupo de niños tratados con ferritina la proteina obtenida puede ser utilizada como fuente nacional...
Subject(s)
Anemia, Iron-Deficiency , Biochemistry , Ferritins , Ferritins/biosynthesis , Ferritins/physiology , Ferritins/ultrastructureABSTRACT
Em alguns tipos de porfirias como porfiria aguda intermitente (PAI) e tirosinemia hereditária tipo (HT1) observa-se acúmulo do ácido 5-aminolevulínico (ALA) no sangue e tecidos. In vitro, o ALA sobre oxidaçäo pelo oxigênio molecular, catalisada por complexos de ferro, gerando o ácido 4,5-dioxovalérico (DOVA), íons NH4+, H2O2 e os radicais ALA, O2, e HO. ALA é capaz também de causar lesöes oxidativas a várias biomoléculas e inclusive induzir a liberaçäo de ferro de ferritina. Sendo assim, o ALA poderia agir como um pró-oxidante endógeno. Nossos estudos foram realizados com o objetivo de: 1) verificar a possibilidade de ocorrer processo autocatalítico durante a oxidaçäo do ALA em presença de ferritina de baço de cavalo (HoSF) e observar a influência de fosfato neste processo...