Carotenoid protein

Green, B. R., and Dnrnford, D. G., 1996. The chlorophyll-carotenoid proteins of oxygenic photosynthesis. Annual Review of Plant Physiology and Plant Molecular Biology 47 685—714. 

Green, B.R. and Dunford, D.G., The chlorophyll-carotenoid proteins of oxygenic photosynthesis, Anmi. Rev. Plant Physiol. Plant Mol. Biol., 47, 685, 1996. 

Specific carotenoid-protein complexes have been reported in plants and invertebrates (cyanobacteria, crustaceans, silkworms, etc.), while data on the existence of carotenoproteins in vertebrates are more limited. As alternatives for their water solubilization, carotenoids could use small cytosolic carrier vesicles." Carotenoids can also be present in very fine physical dispersions (or crystalline aggregates) in aqueous media of oranges, tomatoes, and carrots. Thus these physicochemical characteristics of carotenoids as well as those of other pigments are important issues for the understanding of their bioavailability. 

The hydrolysis of zeaxanthin esters by a carboxyl ester lipase indeed enhanced both the incorporation of zeaxanthin in the micellar phase and uptake of zeaxanthin by Caco-2 cells. As mentioned earher, carotenoids can also be linked to proteins by specific bindings in nature and these carotenoid-protein complexes may slow the digestion process and thus make their assimilation by the human body more difficult than the assimilation of free carotenoids. Anthocyanins are usually found in a glycosylated form that can be acetylated and the linked sugars are mostly glucose, galactose, rhamnose, and arabinose. 

A more difficult problem to overcome is the overestimation of carotenoid concentrations in processed foods due to the usually more efficient extraction of carotenoids in such foods as a result of the denaturation of the carotenoid-protein complexes and cell damage. In addition, weight changes due to loss or gain of water or fat, enzymatic oxidation of carotenoids in raw samples, and leaching of soluble solids during processing should be considered. 

Despite their absence in phycobilisomes, carotenoids, especially the so-called secondary carotenoids such as echinenone, were presumed to play a role in cyanobacterial photoprotection. Indeed, classic biochemical approaches have led to several reports of cyanobacterial carotenoid-proteins and evidence for their photoprotective function (Kerfeld et al. 2003, Kerfeld 2004b). One of these, the water soluble orange carotenoid protein (OCP), has been structurally characterized and has recently emerged as a key player in cyanobacterial photoprotection. 

Orange carotenoid protein Conserved hypothetical protein (sir 1964) ft- OCP N terminal domain OCP C-terminal domain Hypothetical protein Hypothetical protein D- Beta carotene ketolase homolog Hydrolase... 

Bailey, S., N. Mann, C. Robinson, and D. J. Scanlan (2005). The occurrence of rapidly reversible non-photochemical quenching of chlorophyll a fluorescence in cyanobacteria. FEBS Lett 579(1) 275-280. Boulay, C., L. Abasova, C. Six, I. Vass, and D. Kirilovsky (2008a). Occurrence and function of the orange carotenoid protein in photoprotective mechanisms in various cyanobacteria. Biochim Biophys Acta 1777(10) 1344-1354. 

Holt, T. K. and D. W. Krogmann (1981). A carotenoid-protein from cyanobacteria. Biochim Biophys Acta 637(3) 408 114. 

Kerfeld, C. A. (2004b). Water-soluble carotenoid proteins of cyanobacteria. Arch Biochem Biophys 430(1) 2-9. 

Kirilovsky, D. (2007). Photoprotection in cyanobacteria The orange carotenoid protein (OCP)-related non-photochemical-quenching mechanism. Photosynth Res 93 7-16. 

Knutson, R. (1998). The red carotenoid protein from Arthrospira maxima. MS thesis, Purdue University, West Lafayette, IN. 

Polfvka, T., C. A. Kerfeld, T. Pascher, and V. Sundstrom (2005). Spectroscopic properties of the carotenoid 3 -hydroxyechinenone in the orange carotenoid protein from the cyanobacterium Arthrospira maxima. Biochemistry 44(10) 3994—4003. 

Wilson, A., G. Ajlani, J. M. Verbavatz et al. (2006). A soluble carotenoid protein involved in phycobilisome-related energy dissipation in cyanobacteria. Plant Cell 18(4) 992-1007. 

Wilson, A., C. Punginelli, A. Gall et al. (2008). A photoactive carotenoid protein acting as light intensity sensor. Proc Natl Acad Sci 105(33) 12075-12080. 

The v4 region enhancement and structure in the resonance Raman spectra of xanthophylls reviewed in this chapter shows that it can be used for the analysis of carotenoid-protein interactions. Figure 7.8 summarizes the spectra for all four major types of LHCII xanthophylls. Lutein 2 possesses the most intense and well-resolved v4 bands. The spectrum for zeaxanthin is very similar to that of lutein with a slightly more complex structure. This similarity correlates with the structural similarity between these pigments. It is likely that they are both similarly distorted. The richer structure of zeaxanthin spectrum may be explained by the presence of the two flexible P-end rings... 

Lobster and shrimp dine on carotenoid-containing plankton, and the compounds become concentrated in their shells. Here the carotenoids are bound up with protein molecules, and the carotenoid-protein complex has a dark green color. When the protein is heated, it is denatured. In other words, it breaks down and disassociates from the reddish pigment, astaxanthin, which then becomes visible. To a smaller extent this is also evident in cooked carrots, which become more orange than they were before. This was another experiment my daughter and I decided to try. We cooked up some fresh carrots to see if they would become more orange. They did, but the effect was not as pronounced as it was with the shrimp, because carrots have little protein. 

Crustaceans contain carotenoids bound to protein resulting in a blue or blue-gray color. When the animal is immersed in boiling water, the carotenoid-protein bond is broken and the orange-red color of the free car-... 

Common unit operations of food processing are reported to have only minor effects on the carotenoids (Borenstein and Bunnell 1967). The carotenoid-protein complexes are generally more stable than the free carotenoids. Because carotenoids are highly unsaturated, oxygen and light are major factors in their breakdown. Blanching destroys enzymes that cause carotenoid destruction. Carotenoids in frozen or heat-sterilized foods are quite stable. The stability of carotenoids in dehydrated foods is poor, unless the food is packaged in inert gas. A notable exception is dried apricots, which keep their color well. Dehydrated carrots fade rapidly. 

Infrared and Resonance Raman Spectroscopy. Reviewson the uses of resonance Raman spectroscopy in biochemistry and biology include sections on carotenoproteins, visual pigments, and bacteriorhodopsin. The resonance Raman spectrum of the lowest excited triplet state of /3-carotene has been reported.A resonance Raman method has been used for the quantitative analysis of /3-carotene and lutein (20) in tobacco.The mechanism of carotenoid-protein interactions in the carotenoproteins ovoverdin and /3-crustacyanin has been investigated by resonance Raman spectroscopy. " 2 axanthin (24) has been used as a resonance Raman probe of membrane structure. " The resonance Raman spectra have been reported of all-frans-anhydrovitamin A (194), " /3-ionone, retinals, and Schiff bases.The technique has been used extensively to study... 

To differentiate between brown and green algae, we assume that brown algae contain a sizable fraction of carotenoid protein and green algae do not. Thus, the relative abundance of brown algae (C ) is... 

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