. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 290 S. G. DOVE ET AL. and the molar concentration (A/) of pocilloporin were derived from 280-nm and 560-nm chromatograms of pu- rified pocilloporin (Fig. 1 A). The molar concentration of pocilloporin was calculated in the following manner. The amount of pocilloporin (micrograms) was calculated by converting the area of a very slim "slice" of the 280-nm chromatogram (Area A. Fig. 1 A) to protein concentration, using a relationship previously determined between the total area under a 280-nm chromatogram and known amo
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 290 S. G. DOVE ET AL. and the molar concentration (A/) of pocilloporin were derived from 280-nm and 560-nm chromatograms of pu- rified pocilloporin (Fig. 1 A). The molar concentration of pocilloporin was calculated in the following manner. The amount of pocilloporin (micrograms) was calculated by converting the area of a very slim "slice" of the 280-nm chromatogram (Area A. Fig. 1 A) to protein concentration, using a relationship previously determined between the total area under a 280-nm chromatogram and known amounts of protein from several different colonies ofPi>- ctllopora damicomis injected through the column (protein in micrograms = X area + , r2 = ). The volume of each slice was calculated by multiplying the .v- axis (time elapsed. Fig. 1A) of the slice by the flow rate ( ml- min"1). The resulting concentration of pocillo- porin (grams per liter) was then converted into the molar concentration (A/) of pocilloporin by using the native molecular weight of pocilloporin (= 54 kD, see Results). This method was used to determine the extinction coef- ficient because it required only relatively small amounts of protein and thus could be applied to only the purest of fractions (determined by observation of the symmetrical overlay of the 560-nm and 280-nm chromatograms). To verify the validity of the above method, the extinc- tion coefficient for pocilloporin at 560 nm was also de- termined using a more conventional technique employing two methods of measuring protein concentration (Brad- ford, 1976; Whitaker and Granum. 1980). Five aliquots of raw extract that had been molecular weight filtered (using Centricons) were injected into the gel filtration col- umn, and the pocilloporin fractions collected. The col- lected fractions were pooled and concentrated, and the absorbances were measured at 235, 280, and 560-nm with a spectrophotometer (Pharmacia Ultraspec III).
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
