Pavlova Gyrans Research Articles

A New Form of Chlorophyll c Involved in Light-Harvesting

A new form of chlorophyll c has been isolated from the pyrmnesiophyte Pavlova gyrans Butcher. This pigment is spectrally similar to chlorophyll c(2), but all the absorption maxima (454, 583, and 630 nm in diethyl ether) are shifted 4 to 6 nanometers to longer wavelengths. The new pigment can be separated from other chlorophyll c-type pigments by reversed-phase high performance liquid chromatography and thin layer chromatography. Both chlorophylls c(1) and c(2) are found with the new chlorophyll c pigment in P. gyrans, and it has also been detected in the chrysophyte Synura petersenii Korsh. The light-harvesting function of the new chlorophyll c pigment is indicated by its presence along with chlorophyll c(1) and c(2) in a light-harvesting pigment-protein complex isolated from P. gyrans in which chlorophyll c pigments efficiently transfer absorbed light energy to chlorophyll a.

Separation of Chlorophylls c1 and c2 from Pigment Extracts of Pavlova gyrans by Reversed-Phase High Performance Liquid Chromatography

Chlorophylls c(1) and c(2) have been separated from total pigment extracts of the alga Pavlova gyrans Butcher using a reversed-phase high-performance liquid chromatography system. Pigments were separated on a 5 micrometer C(18) column (25 centimeters x 4.6 millimeters) using a gradient of methanol-acetonitrile-water. Other photosynthetic pigments were also well resolved by the system used. The separation system described may replace current thin layer chromatography methods for qualitative and quantitative determination of chlorophyll c species.

EVIDENCE FOR A COMMON EVOLUTIONARY ORIGIN OF LIGHT‐HARVESTING FUCOXANTHIN CHLOROPHYLL a/c‐PROTEIN COMPLEXES OF PAVLOVA GYRANS (PRYMNESIOPHYCEAE) AND PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE)1

ABSTRACTA fucoxanthin‐chlorophyll a/c‐protein complex has been isolated from the prymnesiophyte Pavlova gyrans. Thylakoid membranes were treated with the mild anionic detergent sodium taurodeoxycholate followed by sucrose density gradient centrifugation. The brown fraction produced by this procedure was treated with Triton X‐100 followed by a second sucrose density gradient centrifugation. A brown fraction isolated from this gradient was shown to be a light‐harvesting complex nearly identical to that which is present in the diatom Phaeodactylum tricornutum. The complexes from the two organisms have nearly identical absorption and flourescence spectra, both complexes contain fucoxanthin and two other carotenoids, both contain four polypeptides of similar molecular weights, and polypeptides from both complexes cross react with antibodies raised to polypeptides of the Phaeodactylum tricornutum complex. Results suggest a common evolutionary origin for these light‐harvesting complexes, in apparent contrast to the great differences in cell structure between prymnesiophytes and diatoms.