. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VANADATE REDUCTION BY VANADOBIN 191 Peak 2 Peak 5. mg v = 40 ~~60 80 Fraction number 100 120 140 Figure 2. Elution profile of the supernatant of a homogenate of blood cells from Ascidia gemmata from a column of Sephadex G-15. The supernatant (7 ml) was loaded onto a column ( cm X 56 cm long) of Sephadex G-15 (Pharmacia Fine Chemicals) and eluted with DDW (see text) at pH in 5 ml. Fractions composing each peak were sepa- rately pooled, and amounts of vanadium in individual aliquots were measured by ESR spectr
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. VANADATE REDUCTION BY VANADOBIN 191 Peak 2 Peak 5. mg v = 40 ~~60 80 Fraction number 100 120 140 Figure 2. Elution profile of the supernatant of a homogenate of blood cells from Ascidia gemmata from a column of Sephadex G-15. The supernatant (7 ml) was loaded onto a column ( cm X 56 cm long) of Sephadex G-15 (Pharmacia Fine Chemicals) and eluted with DDW (see text) at pH in 5 ml. Fractions composing each peak were sepa- rately pooled, and amounts of vanadium in individual aliquots were measured by ESR spectrometry. Then, the material under each peak was lyophilized and kept under anaerobic conditions. The material in the second peak contained the highest amount of vanadium. V,: 570 ml, V0: 226 ml, and Vc: 280ml. 620 nm and 760 nm, which are assignable to vana- dium(III) and vanadyl(IV), respectively. Comparing the corresponding spectra observed in inorganic vanadium complexes, as demonstrated previously (Michibata et ai, 1990a), we calculated that the supernatant of the homog- enate of the blood cells intrinsically contained 25 mAf vanadium in the +3 and +4 oxidation states at a ratio of 30:70. After adding ml of an 8 mAf solution of vanadate( V) to an equal volume of the supernatant, spectral changes were recorded. Figures 1A and IB show the spectra im- mediately after mixing and after 31 h. The absorbance at 760 nm due to vanadyl(IV) became conspicuous, accom- panying the decrease of the absorbance at the wavelength shorter than 530 nm due to vanadate(V) with time, sug- gesting that the added vanadate(V) was reduced to van- adyl(IV) by the supernatant. By contrast, the addition of the same amount of an 8 mAf solution of vanadyl(IV) resulted in little change. These observations indicate clearly that some reducing agent is present in the super- natant of homogenate of blood cells from Ascidia gem- mat a, which can reduce vanadate(V) to vanadyl(IV). As shown in Figure 1B, the s
Size: 1780px × 1404px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
