RESUMO
Synechococcus ATCC 29403 (PCC 7335) is a unicellular cyanobacterium isolated from Puerto Peñasco, Sonora Mexico. This cyanobacterium performs complementary chromatic acclimation (CCA), far-red light photoacclimation (FaRLiP), and nitrogen fixation. The Synechococcus PCC 7335 genome contains at least 31 genes for proteins of the phycobilisome (PBS). Nine constitutive genes were expressed when cells were grown under white or red lights and the resulting proteins were identified by mass spectrometry in isolated PBS. Five inducible genes were expressed under white light, and phycoerythrin subunits and associated linker proteins were detected. The proteins of five inducible genes expressed under red light were identified, the induced phycocyanin subunits, two rod linkers and the rod-capping linker. The five genes for FaRLiP phycobilisomes were expressed under far-red light together with the apcF gene, and the proteins were identified by mass spectrometry after isoelectric focusing and SDS-PAGE. Based on in silico analysis, Phylogenetic trees, and the observation of a highly conserved amino acid sequence in far-red light absorbing alpha allophycoproteins encoded by FaRLiP gene cluster, we propose a new nomenclature for the genes. Based on a ratio of ApcG2/ApcG3 of six, a model with the arrangement of the allophycocyanin trimers of the core is proposed.
Assuntos
Proteínas de Bactérias/genética , Ficobilissomas/metabolismo , Synechococcus/fisiologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Simulação por Computador , Eletroforese em Gel de Poliacrilamida/métodos , Genoma Bacteriano , Luz , Espectrometria de Massas , Modelos Biológicos , Ficobilinas/metabolismo , Ficobilissomas/genética , Ficocianina/genética , Ficocianina/metabolismo , Ficoeritrina/genética , Ficoeritrina/metabolismo , Proteômica/métodos , Synechococcus/metabolismo , Zinco/químicaRESUMO
The aim of this work was to investigate the production of phycocyanin by Spirulina platensis under different spectra of light. The dependent variables evaluated were the amount of phycocyanin obtained and its purity, demonstrating that there might be a restructuring of phycobilisomes, especially when the culture was subjected to red light, which increased the purity level up to 33 percent with a reduction of 16 percent in phycocyanin content, but with higher photosynthetic efficiency compared to natural light.