Purification, characterization and comparison of phycoerythrins from three different marine cyanobacterial cultures
ABSTRACT The present study is focused on purification, characterization and comparison of phycoerythrins from three different marine cyanobacterial cultures--hormidium sp. A27 DM, Lyngbya sp. A09 DM and Halomicronema sp. A32 DM. 'Phycoerythrin' was successfully purified and characterized. On SDS-PAGE, the PE purified from all three young cultures showed four bands--corresponding to α and β subunits of each of PE-I and PE-II. However, phycoerythrin purified after prolonged growth of Phormidium sp. A27 DM and Halomicronema sp. A32DM showed only one band corresponding to 14 kDa whereas Lyngbya sp. A09 DM continued to produce uncleaved phycoerythrin. The absorption spectra of purified PEs from all the three young and old cultures showed variations however the fluorescence studies of the purified PEs in all cases gave the emission spectra at around 580 nm. The described work is of great importance to understand the role of phycoerythrin in adapting cyanobacteria to stress conditions.
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- "Moreover, imperative properties of PBPs like hepato-protective , anti-oxidants  and anti-inflammatory activity , make them very potential macromolecules for therapeutic, diagnostic and pharmacological applications. Various methods have been reported for purification of PE , PC  and APC  but mainly focused on purification of single PBP at a time. Therefore, this study was aiming to purify PE, PC and APC concurrently form Lyngbya sp. "
ABSTRACT: The present study probes into the purification of phycobiliproteins, and characterization of their in vitro anti-oxidant activity. Moreover the study also demonstrates the use of antioxidant virtue of phycoerythrin in moderating the phenomenon of aging in Caenorhabditis elegans. Phycoerythrin, phycocyanin and allophycocyanin were purified successfully from Lyngbya sp. A09DM by ammonium sulfate fractionation appended with Triton X-100 intercession. The success of protocol was examined by a series of biochemical characterization like SDS-PAGE, native-PAGE, UV-visible spectroscopy and fluorescence spectroscopy ensuring purity, integrity and functionality of purified phycoerythrin, phycocyanin and allophycocyanin. Purified phycobiliproteins were evaluated for antioxidant and metal ion chelating activity by various in vitro antioxidant assay systems. Results showed significant and dose-dependent antioxidant as well as metal chelating potential of all phycobiliproteins in decreasing order of phycoerythrin > phycocyanin > allophycocyanin. Expansion in lifespan and improvement in pharyngeal pumping of Caenorhabditis elegans were noticed upon pre-treatment with phycoerythrin (100 μg ml−1). Moreover, phycoerythrin mediated increase in worm survival under oxidative stress revealed that the life expansion effect of phycoerythrin on nematode is in part by an action of its antioxidant virtue. These results collectively added up evidence in favor of the ‘Free - radical theory of aging’. The present report, for the first time, describes antioxidant potential of phycoerythrin and its use in extending life-span of Caenorhabditis elegans.PROCESS BIOCHEMISTRY 07/2014; 49(10). DOI:10.1016/j.procbio.2014.06.022 · 2.52 Impact Factor
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ABSTRACT: Complementary chromatic adaptation, a photomorphogenetic response, known to occur in many cyanobacteria, enables them to efficiently absorb prevalent wavelengths of light in the environment. In the present study, we have described the influence of light on phycobiliprotein production in three marine phycoerythrin producing cyanobacterial cultures, namely, Lyngbya sp. A09DM, Phormidium sp. A27DM and Halomicronema sp. A32DM. A comparative study (UV-visible overlay spectra and SDS-PAGE analyses) of phycobiliproteins purified from all the three cultures grown in white, yellow, red and green lights has been confirmed. White light was taken as control. Red and green lights were taken to check their effect on phycocyanin and phycoerythrin production, respectively. Yellow light was studied as its wavelength falls in between green and red light. Lyngbya sp. A09DM was found to be the best chromatically adapting cyanobacterium followed by Halomicronema sp. A32DM. These two cultures can be placed in group III chromatic adaptors. Phormidium sp. A27DM was the least chromatically adapting culture and can be placed in group II chromatic adaptors. The study signifies that even light plays an important role along with nutrient availability in adapting cultures to changing environmental conditions.Acta Physiologiae Plantarum 06/2013; 35(6). DOI:10.1007/s11738-013-1219-8 · 1.52 Impact Factor
Conference Paper: MSIM2: mixed-signal short channel IGFET model for circuitsimulations[Show abstract] [Hide abstract]
ABSTRACT: MSIM2 is a physical compact model specifically developed for mixed-signal and analog-intensive circuit simulations in deep sub-micron CMOS technologies. MSIM2 separates the drift and diffusion current components as continuous functions in all all operating regions, and shows superior accuracy and continuity in the subthreshold and moderate inversion regions even for second-order derivatives. It has full temperature scalability (-55°C to 150°C) and geometry scalability (down to 0.25 μm in W and L), and uses less parameters than other advanced models. MSIM2 also includes scalable charge and noise models, and has been verified against various processes from around the worldSemiconductor Conference, 1996., International; 11/1996