Jellyfish

The jellyfish can be extracted to yield a photoproteia, a complex of luciferia and apoaequoria that generates light (rapid flash, 460 nm) on... 

Green Fluorescent Protein—The Light Fantastic from Jellyfish to Gene Expression... 

Blinks used a different method to dislodge the particles of active material from the strips cut off from the jellyfish (Blinks et al., 1978). The strips are shaken in cold seawater, and the particles dislodged are harvested by filtration on a Buchner funnel with the aid of Celite. The filter cake is first washed with 50 mM EDTA, pH 8.0, containing (NH4)2S(>4 at 75% saturation, to remove seawater. Then, the particles are cytolyzed and aequorin is extracted in situ by washing the filter cake with cold 50 mM EDTA, pH 8.0. The filtrate is clear and slightly greenish. The active matter in the filtrate is precipitated by saturation... 

A cDNA encoding apoobelin was obtained from O. longissima and sequenced (Illarionov et al., 1995). The deduced amino acid sequence of the apoobelin consists of 195 amino acid residues, with a calculated molecular mass of about 22.2 kDa, closely matching the apoproteins of other Ca2+-sensitive photoproteins such as aequorin from the jellyfish Aequorea (Inouye et al., 1985 Prasher et al., 1985) and clytin from the jellyfish Phialidium gregarium (Inouye and Tsuji, 1993). To obtain recombinant apoobelin, the cDNA encoding apoobelin was expressed in E. coli (Illarionov et al., 2000). The recombinant apoobelin produced was purified and converted into obelin by incubation with coelenterazine in the presence of molecular oxygen and 2-mercaptoethanol or dithioerythritol, as in the case of aequorin. 

The small jellyfish Phialidium gregarium (diameter 15-20 mm) used to be abundant at Friday Harbor, Washington, in summer and autumn until about 1990. Levine and Ward (1982) isolated and purified a Ca2+-sensitive photoprotein from this jellyfish and named it phialidin. They extracted the photoprotein from whole specimens with an EDTA-containing buffer. The photoprotein extract was precipitated with ammonium sulfate, and purified by the following methods gel-filtration (BioGel P-150, minus 400 mesh), anion-exchange chromatography (DEAE Bio-Gel A), and gel-filtration (Sephadex G-75, superfine). 

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