α-Tocopherol is synthesized exclusively in oxygenic phototrophs and is known to function as a lipid-soluble antioxidant. Here we report that α-tocopherol also has a novel function independent of its antioxidant properties in the cyanobacterium Synechocystis sp. PCC 6803. The photoautotrophic growth rates of wild type and mutants impaired in αtocopherol biosynthesis are identical, but the mutant...

Photosynthetic organisms adapt to environmental fluctuations of light and nutrient availability. Iron is critical for photosynthetic organismal growth, as many cellular processes depend upon iron cofactors. Whereas low iron levels can have deleterious effects, excess iron can lead to damage, as iron is a reactive metal that can result in the production of damaging radicals. Therefore, organisms...

The mobility of cell surface MHC molecules and their ability to form dynamic associations may be related to the physiological status of the cell and to the potential to bind effector T lymphocytes. To investigate these properties, we have prepared HLA DR specific monoclonal antibodies coupled in a 1:1 mole ratio to the fluorescent phycobiliprotein, R-phycoerythrin (PE). We show that these small...

BACKGROUND The cyanobacterium species Microcystis aeruginosa produces microcystin and an array of diverse metabolites believed responsible for their toxicity and/or immunogenicity. Previously, chronic rhinitis patients were demonstrated to elicit a specific IgE response to nontoxic strains of M. aeruginosa by skin-prick testing, indicating that cyanobacteria allergenicity resides in a non-toxin...

a-Tocopherol is synthesized exclusively in oxygenic phototrophs and is known to function as a lipid-soluble antioxidant. Here, we report that a-tocopherol also has a novel function independent of its antioxidant properties in the cyanobacterium Synechocystis sp. PCC 6803. The photoautotrophic growth rates of wild type and mutants impaired in a-tocopherol biosynthesis are identical, but the muta...

Antioksidan diperlukan tubuh untuk melindungi kesehatan kulit kita. Salah satu sumber antioksidan adalah mikroalga Spirulina sp. Permasalahan pemanfaatan spirulina teknologi kultur yang tepat menghasilkan aktivitas tinggi. Tujuan penelitian melakukan optimasi pencahayaan (warna cahaya) dalam mendapatkan pertumbuhan terbaik, kadar pigmen dan tertinggi. Penelitian menggunakan metode eksperimen la...

alpha-Tocopherol is synthesized exclusively in oxygenic phototrophs and is known to function as a lipid-soluble antioxidant. Here, we report that alpha-tocopherol also has a novel function independent of its antioxidant properties in the cyanobacterium Synechocystis sp. PCC 6803. The photoautotrophic growth rates of wild type and mutants impaired in alpha-tocopherol biosynthesis are identical, ...

Pigment mutant strain FdR1 of the filamentous cyanobacterium Fremyella diplosiphon is characterized by constitutive synthesis of the phycobiliprotein phycoerythrin due to insertional inactivation of the rcaC regulatory gene by endogenous transposon Tn5469. Whereas the parental strain Fd33 harbors five genomic copies of Tn5469, cells of strain FdR1 harbor six genomic copies of the element; the s...

Allophycocyanin B (AP-B) is one of the two terminal emitters in phycobilisomes, the unique light-harvesting complexes of cyanobacteria and red algae. Its low excitation-energy level and the correspondingly redshifted absorption and fluorescence emission play an important role in funnelling excitation energy from the hundreds of chromophores of the extramembraneous phycobilisome to the reaction ...

We examined the inhibitory activity of angiotensin I converting enzyme (ACE) in protein hydrolysates from dulse, Palmaria palmata. The proteins extracted from dulse were mainly composed of phycoerythrin (PE) followed by phycocyanin (PC) and allophycocyanin (APC). The dulse proteins showed slight ACE inhibitory activity, whereas the inhibitory activity was extremely enhanced by thermolysin hydro...