Chlorophyl a/b protein

Simidjiev, L, Barzda, V., Mustardy, L., and Garab, G. 1997. Isolation of lamellar aggregates of the light-harvesting chlorophyll a/b protein complex of photosystem II with long-range chiral order and structural flexibility. Anal. Biochem. 250 169-75. 

The literature search was now expanded and yielded the conclusion that another possible and more widespread precursor is the light-harvesting chlorophyll a/b-protein (LHCP), which is present in almost all photosynthetically grown higher plants and green algae (ref. 373-375). It is by far the major pigment-protein in these plants and accounts for 40-60% of the total chlorophyll (ref. 373,374). 

Table 5.2 lists the amino acid molar ratios determined for LHCP from several plant sources, and compares these results with the mean values obtained for the main glycopeptide subfraction (peak I in Table 5.1) from microbubble surfactant. It can be seen from Table 5.2 that the amino acid composition of LHCP clearly resembles that of the main glycopeptide subfraction. Specifically, in both cases nonpolar residues represent a majority and near constant fraction (i.e., 59-62%) of the amino acid composition, with the relative amounts of such residues in practically all individual cases listed following the pattern glycine > leucine, alanine, valine, proline > isoleucine, phenylalanine > methionine, tryptophan (Table 5.2). Accordingly, the glycopeptide fraction of microbubble surfactant may represent a degradation product of the light-harvesting chlorophyll a/b-protein, which is well known (ref. 373-375) to be extremely widely distributed in terrestrial, freshwater, and salt-water environments (cf. ref. 379).

I.J. Ryrie and N. Fuad, Membrane adhesion in reconstituted proteoliposomes containing the light-harvesting chlorophyll a/b-protein complex the role of charged surface groups, Arch. Biochem. Biophys. 214 (1982) 475-488. 

K.S. Kan and J.P. Thomber, Hie light-harvesting chlorophyll a/b-protein complex of Chlamydomonas reinhardii, Plant Physiol. 57 (1976)47-52. 

Del Duca, S., Tidu, V., Bassi, R., Esposito, C., and Serafini-Fracassini, D., Identification of chlorophyll-a/b proteins as substrates of transglutaminase activity in isolated chloroplasts of Helianthus tuberosus L., Planta, 193, 283-289, 1994. 

Dunahay, T. and L A. Staehelin. 1986. Isolation and characterization of a new minor chlorophyll a/b-protein complex (CP24) from spinach. Plant Physiol. 80,429 134. 

Bassi R, Soen SY, Frank G, Zuber H and Rochaix J-D. (1992). Characterization of chlorophyll a/b proteins of photosystem I from Chlamydomonas reinhardtii. J. Biol. Chem. 267, 25714-25721. 

Sukenik A, Bennett J, Falkowski PG. (1988). Changes in the abundance of individual apoproteins of light-harvesting chlorophyll a/b-protein complexes of photosystem I and II with growth irradiance in the marine chlorophyte Dunaliella tertiolecta. Biochim. Biophys. Acta 932, 206-215. 

Fig. 2. (A) A hydropathy plot of the amino-acid sequence of pea LHC II. (B) A sketch of the amino-acid sequence of the LHC II from Lemna gibba (an aquatic monocot). (A) from R Bargi, F Suter and H Zuber (1987) Arrangement of the light-harvesting Chlorophyll a/b protein complex in the thylakoid membrane. Biochim Biophys Acta 890 348 (B) from GA Karlin-Neumann, BD Kohorn, JP Thornber and EM Tobin (1985) A chlorophyll a/b-protein encoded by a gene containing an Intron with characteristics of a (rans-posable element. J Mol AppI Genet. 3 58.

JE Mullet, JJ Burke and CJ Arntzen (1980) Chlorophyll proteins of photosystem I. Plant Physiol 65 814-822 E Lam, W Ortiz, S Mayfield and R Malkin (1984) Isolation and characterization of a light-harvesting chlorophyll a/b protein complex associated with photosystem I. Plant Physiol 74 650-655 E Lam, W Ortiz and R Malkin (1984) Chlorophyll alb proteins of photosystem I. FEBS Lett 168 10-14 H Michel (1982) 3-dimensional crystals of a membrane protein complex. The photosynthetic reaction center from Rhodopseudomonas viridis. J Mol Biol 158 567-572... 

Note that the ring planes of the chlorophyll molecules in Fig. 5 (A) were shown oriented mostly perpendicular to the membrane plane. This orientation appears to be similar to that in the PS-II chlorophyll a/b protein (LHC II), as determined by Kiihlbrandt and Wang and predicted by Haworth, Tapie, Amtzen and Breton on the basis of circular-dichroism measurements. The center-to-center distances between the porphyrin planes of the CA-Chl a molecules in the PS-I reaction center range from 8 to 15 A, which are comparable to those in PS tf and in the BChl-a protein complex as measured by Mathews, Fenna, Bolognesi and Olson (see Chapter 8, Section V). Some of the closely spaced chlorophyll-a molecules appear to form chains mnning between the stroma and lumen sides of photosystem I. Between 12 and 16 P-carotene molecules are thought to be present in the PS-I reaction center, but they have not been identified by X-ray crystallographic measurements. 

Siefermann-Harms D (1990c) Protective function of the apoprotein of the light-harvesting chlorophyll-a/b-protein complex in pigment photo-oxidation. J Photochem Photobiol B Biol 4 283-295... 

The PSIl reaction center complex obtained by this procedure seems to be highly uniform in terms of surface charge and focuses at pH 4.9 as a sharp green band. A small peak on the higher pH side of the main band was enriched in the lightharvesting chlorophyll a/b protein. 

THE ROLE OF LIGHT HARVESTING COMPLEX II AND OF THE MINOR CHLOROPHYLL a/b PROTEINS IN THE ORGANIZATION OF THE PHOTOSYSTEM II ANTENNA SYSTEM. 

Table I Characteristics of chlorophyll a/b proteins from maize PSII membranes. Samples were obtained by a single lEF step. Multistep procedures yielded chi a/b ratio values higher for CP26 and CP29 lower for CP24.

Table III relative protein content (%) of chi a/b binding polypeptides in sucrose gradient bands 2, 3 and 4 containing chlorophyll a/b proteins) from DM solubilized PSII membranes.

STRUCTURE OF THE LIGHT-HARVESTING CHLOROPHYLL a/b PROTEIN COMPLEX BY HIGH-RESOLUTION ELECTRON CRYSTALLOGRAPHY... 

PROPERTIES OF THE MINOR CHLOROPHYLL A/B PROTEINS CP29, CP26 AND CP24 FROM Zea mays PHOTOSYSTEM II MEMBRANES. 

THE 20 kDA APO-POLYPEPTIDE OF THE CHLOROPHYLL a/b PROTEIN COMPLEX CP24 - CHARACTERIZATION AND COMPLETE PRIMARY AMINO ACID SEQUENCE... 

THE MAJOR LIGHT-HARVESTING CHLOROPHYLL a/b PROTEIN (LHC lib) THE SMALLEST SUBUNIT IS A NOVEL CAB GENE PRODUCT... 

FAB19 Complete chlorophyll a/b protein coding region and 5 and 3 flanking nucleotides for the aquatic monocot Lemna gibba, courtesy of Dr. Elaine M. Tobin (Karlin>-Neumann,G A., et ai., 1985). 

The procedure for the isolation of chloroplasts from cell wall mutants of Chlamydomonas yields relatively pure, active chloroplasts. These chloroplast were photosynthetically active (3) and synthesized proteins in organello (4). They also imported, processed and assembled in vitro synthesized precursors for the small subunit of ribulose bisphosphate carboxylase and for the light harvesting chlorophyll a/b proteins (5, 6, 7). 

The Role of Light Harvesting Complex II and of the Minor Chlorophyll a/b Proteins in the... 

Structure of the Light-Harvesting Chlorophyll a/b Protein Complex by High-Resolution... 

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