Pigment and acyl lipid composition of photosystem I and II vesicles and of photosynthetic mutants in barley

Abstract

The pigment and acyl lipid composition ofphotochemically active stroma lamellae and inside-out photosystem II vesicles have been investigated. Mechanical disruption followed by phase partitioning in an aqueous two phase system resulted in a clean separation of the photosystems. A qualitative and quantitative determination of the pigment content was achieved using reversed-phase high performance liquid chromatography. A single chromatographic separation provided adequate resolution of neoxanthin, violaxanthin, lutein, chlorophyll b, chlorophyll a, and 13-carotene and was completed in 22 min. For each molecule of P700, the stroma lamellae contained 166 molecules of chlorophyll a, 14 molecules of chlorophyll b, 0 molecules of neoxanthin, 3 molecules of violaxanthin, 7 molecules of lutein, and 13 molecules of 13-carotene. For each molecule of P680 the photosystem II vesicles contained 250 molecules of chlorophyll a, 100 molecules of chlorophyll b, 7 molecules of neoxanthin, 7 molecules of violaxanthin, 22 molecules of lutein, and 4 molecules of l~-carotene. The pigment content of three photosynthetic mutants chlorina-[2, viridis-zb63 and viridis-zd69 was determined. On a chlorophyll basis, these mutants generally showed a reduced carotenoid content, except that chlorina-f2 had an increased level ofl3-earotene and viridis-zd69 an unaltered level of lutein.The acyl lipid composition of stroma lamellae, photosystem II vesicles and lamellar systems was also determined. Although the photochemical activities of the stroma lamellae and photosystem II vesicles were enriched compared to the parent lamellar system, more than 50% of the acyl lipids in the subchloroplastic membranes were degraded or severely modified resulting in a drastically reduced content of monogalactosyldiglyceride and digalactosyldiglyceride in the stroma lamellae and photosystem II vesicles. Due to the lipolytic degradation the level of saturation in the gatactolipids was higher in stroma lamellae and photosystem II vesicles compared with the lamellar system. Stroma lamellae do not contain the light-harvesting chlorophyll a/b-protein, but were enriched in phosphatidylglycerol and trans-3-hexadecenoic acid.Abbreviations: Chl = chlorophyll; ChI-P = chlorophyll-protein; DG = digalactosyldiglyceride; GLC = gas-liquid chromatography; HPLC = high-performance liquid chromatography; MG = monogalactosyldiglyceride; PC = phosphatidylcholine; PG = phosphatidylglycerol; PI = phosphatidylinositol; SL = sulfoquinovosyldiglyceride; TLC = thin layer chromatography.

CHLOROPHYLL BINDING PROTEINS WITH ANTENNA FUNCTION IN HIGHER PLANTS and GREEN ALGAE

“…In vitro reconstitutions of LHCII have shown that xanthophylls are required for denatured apoproteins to be reconstituted with stable reassociation of chlorophyll molecules . This finding is supported by the observation that in general carotenoidless mutants are also depleted in LHCII (Henry et al, 1983;Michel et al, 1983). For the chlorophylllprotein ratio, reported values depended on the method used for LHCII purification: thus, Burke et al (1978) measured a value of 13 chlorophylls per polypeptide with preparation based on sucrose gradient centrifugation, whereas Thornbcr et al (1979) measured 6 for an SDS-PAGE preparation.…”

Biosynthesis of esterified alkan-2-ols and β-diketones in barley spike epicuticular wax: Synthesis of radioactive intermediates

“…(Milford, Mass., USA) instrument (23). Both analytical and preparative separations were carried out by the use of a prepacked ktBondapack C-8 (l0 lain particle size) "Radial Pack Cartridge" (10 crux0.8 cm i.d.)…”

A thylakoid polypeptide involved in the reconstitution of photosynthetic oxygen evolution

“…The French Press was operated at 3,600 lb. in-2 and the polymer concentration used was 5.80% (20). The inside-out photosystem II vesicles partitioned to the bottom phase, and were repartitioned with fresh upper phase until essentially all chlorophyll Figure 3: Polypeptide composition of inside-out photosystem II vesicles and of photosystem II membranes prepared with Triton X-100 and of the polypeptides released by Tris/NaCl washing or from thylakoids by sonication in the presence of NaC1.…”

“…Inside-out photosystem II vesicles from barley ( Figure 3) had a similar composition although they were always contaminated to some extent with photosystem I components (20). Electron microscopy revealed that the preparation consisted of pairs of tightly appressed membrane sheets with only a limited volume at the edges (49).…”