Phycoerythrin

Last updated
Phycoerythrin, alpha/beta chain
Identifiers
SymbolPhycoerythr_ab
Pfam PF02972
InterPro IPR004228
SCOP2 1qgw / SCOPe / SUPFAM
Available protein structures:
Pfam   structures / ECOD  
PDB RCSB PDB; PDBe; PDBj
PDBsum structure summary

Phycoerythrin (PE) is a red protein-pigment complex from the light-harvesting phycobiliprotein family, present in cyanobacteria, [1] red algae [2] and cryptophytes, [3] accessory to the main chlorophyll pigments responsible for photosynthesis.The red pigment is due to the prosthetic group, phycoerythrobilin, which gives phycoerythrin its red color. [4]

Contents

Like all phycobiliproteins, it is composed of a protein part covalently binding chromophores called phycobilins. In the phycoerythrin family, the most known phycobilins are: phycoerythrobilin, the typical phycoerythrin acceptor chromophore. Phycoerythrobilin is a linear tetrapyrrole molecule found in cyanobacteria, red algae, and cryptomonads. Together with other bilins such as phycocyanobilin it serves as a light-harvesting pigment in the photosynthetic light-harvesting structures of cyanobacteria called phycobilisomes. [5] Phycoerythrins are composed of (αβ) monomers, usually organised in a disk-shaped trimer (αβ)3 or hexamer (αβ)6 (second one is the functional unit of the antenna rods). These typical complexes also contain a third type of subunit, the γ chain. [2]

Phycobilisomes

Phycobiliproteins (like phycoerythrin) usually form rods of stacked disks in phycobilisomes. Phycobilisome structure.jpg
Phycobiliproteins (like phycoerythrin) usually form rods of stacked disks in phycobilisomes.

Phycobiliproteins are part of huge light harvesting antennae protein complexes called phycobilisomes. In red algae they are anchored to the stromal side of thylakoid membranes of chloroplasts, whereas in cryptophytes phycobilisomes are reduced and (phycobiliprotein 545 PE545 molecules here) are densely packed inside the lumen of thylakoides. [3] [7]

Phycobiliproteins have many practical application to them including imperative properties like hepato-protective, anti-oxidants, anti-inflammatory and anti-aging activity of PBPs enable their use in food, cosmetics, pharmaceutical and biomedical industries. PBPs have been also noted to show beneficial effect in therapeutics of some disease like Alzheimer and cancer. [8]

Phycoerythrin is an accessory pigment to the main chlorophyll pigments responsible for photosynthesis. The light energy is captured by phycoerythrin and is then passed on to the reaction centre chlorophyll pair, most of the time via the phycobiliproteins phycocyanin and allophycocyanin.

Structural characteristics

Phycoerythrins except phycoerythrin 545 (PE545) are composed of (αβ) monomers assembled into disc-shaped (αβ)6 hexamers or (αβ)3 trimers with 32 or 3 symmetry and enclosing central channel. In phycobilisomes (PBS) each trimer or hexamer contains at least one linker protein located in central channel. B-phycoerythrin (B-PE) and R-phycoerythrin (R-PE) from red algae in addition to α and β chains have a third, γ subunit contributing both linker and light-harvesting functions, because it bears chromophores. [2]

The crystal structure of B-phycoerythrin from red algae Porphyridium cruentum (PDB ID: 3V57 ). The asymmetric unit (ab)2 on the left and assumed biological molecule (ab)3. It contains phycoerythrobilin, N-methyl asparagine and SO 4. B-phycoerythrin 3V57.png
The crystal structure of B-phycoerythrin from red algae Porphyridium cruentum (PDB ID: 3V57 ). The asymmetric unit (αβ)2 on the left and assumed biological molecule (αβ)3. It contains phycoerythrobilin, N-methyl asparagine and SO
4.

R-phycoerythrin is predominantly produced by red algae. The protein is made up of at least three different subunits and varies according to the species of algae that produces it. The subunit structure of the most common R-PE is (αβ)6γ. The α subunit has two phycoerythrobilins (PEB), the β subunit has 2 or 3 PEBs and one phycourobilin (PUB), while the different gamma subunits are reported to have 3 PEB and 2 PUB (γ1) or 1 or 2 PEB and 1 PUB (γ2). The molecular weight of R-PE is 250,000 daltons.

Crystal structures available in the Protein Data Bank [12] contain in one (αβ)2 or (αβγ)2 asymmetric unit of different phycoerythrins:

Phycoerythrobilin is the typical chromophore in phycoerythrin. It is similar to porphyrin of chlorophyll for example, but tetrapyrrole is linear, not closed into ring with metal ion in the middle. Phycoerythrobilin2.svg
Phycoerythrobilin is the typical chromophore in phycoerythrin. It is similar to porphyrin of chlorophyll for example, but tetrapyrrole is linear, not closed into ring with metal ion in the middle.
The red algae Gracilaria contains R-phycoerythrin. Gracilaria2.JPG
The red algae Gracilaria contains R-phycoerythrin.
Chromophore or other
non-protein molecule		PhycoerythrinChain
PE545B-PER-PEother types
Bilins 8101010α and β
- Phycoerythrobilin (PEB)6100 or 88β (PE545)
or α and β
- 15,16-dihydrobiliverdin (DBV)2———α (-3 and -2)
- Phycocyanobilin (CYC)——8 or 7 or 0—α and β
- Biliverdine IX alpha (BLA)——0 or 1—α
- Phycourobilin (PUB)——22β
5-hydroxylysine (LYZ)1 or 2———α (-3 or
-3 and -2)
N-methyl asparagine (MEN)220 or 22β
Sulfate ion SO42− (SO4)—5 or 10 or 2—α or α and β
Chloride ion Cl− (CL)1———β
Magnesium ion Mg2+ (MG)2———α-3 and β
inspected PDB files1XG0
1XF6
1QGW		3V57
3V58		1EYX
1LIA
1B8D		2VJH
The crystal structure of phycoerythrin 545 (PE545) from a unicellular cryptophyte Rhodomonas CS24 (PDB ID: 1XG0 ). Colors: chains - alpha-2, alpha-3, beta, beta (helixes, sheets are yellow), phycoerythrobilin, 15,16-dihydrobiliverdin (15,16-DHBV), 5-hydroxylysine, N-methyl asparagine, Mg, Cl. Phycoerythrin 545 1XG0.gif
The crystal structure of phycoerythrin 545 (PE545) from a unicellular cryptophyte Rhodomonas CS24 (PDB ID: 1XG0 ). Colors: chains – alpha-2, alpha-3, beta, beta (helixes, sheets are yellow), phycoerythrobilin, 15,16-dihydrobiliverdin (15,16-DHBV), 5-hydroxylysine, N-methyl asparagine, Mg, Cl.

The assumed biological molecule of phycoerythrin 545 (PE545) is (αβ)2 or rather (α3β)(α2β). The numbers 2 and 3 after the α letters in second formula are part of chain names here, not their counts. The synonym cryptophytan name of α3 chain is α1 chain.

The largest assembly of B-phycoerythrin (B-PE) is (αβ)3 trimer [9] [10] . However, preparations from red algae yield also (αβ)6 hexamer [2] . In case of R-phycoerythrin (R-PE) the largest assumed biological molecule here is (αβγ)6, (αβγ)3(αβ)3 or (αβ)6 dependently on publication, for other phycoerythrin types (αβ)6. These γ chains from the Protein Data Bank are very small and consist only of three or six recognizable amino acids [15] [16] , whereas described at the beginning of this section linker γ chain is large (for example 277 amino acid long 33  kDa in case of γ33 from red algae Aglaothamnion neglectum ) [17] [2] . This is because the electron density of the gamma-polypeptide is mostly averaged out by its threefold crystallographic symmetry and only a few amino acids can be modeled [15] [16] [18] [19] .

For (αβγ)6, (αβ)6 or (αβγ)3(αβ)3 the values from the table should be simply multiplied by 3, (αβ)3 contain intermediate numbers of non-protein molecules. (this non sequitur needs to be corrected)

In phycoerythrin PE545 above, one α chain (-2 or -3) binds one molecule of billin, in other examples it binds two molecules. The β chain always binds to three molecules. The small γ chain binds to none.

Two molecules of N-methyl asparagine are bound to the β chain, one 5-hydroxylysine to α (-3 or -2), one Mg2+ to α-3 and β, one Cl− to β, 1–2 molecules of SO2−
4 to α or β.

Below is sample crystal structure of R-phycoerythrin from Protein Data Bank:

The crystal structure of R-phycoerythrin from red algae Gracilaria chilensis (PDB ID: 1EYX ) - basic oligomer (abg)2 (so called asymmetric unit). It contains phycocyanobilin, biliverdine IX alpha, phycourobilin, N-methyl asparagine, SO4. One fragment of g chain is red, second one white because it is not considered as alpha helix despite identical aminoacid sequence. R-phycoerythrin 1EYX 1 of 2.gif
The crystal structure of R-phycoerythrin from red algae Gracilaria chilensis (PDB ID: 1EYX ) - basic oligomer (αβγ)2 (so called asymmetric unit). It contains phycocyanobilin, biliverdine IX alpha, phycourobilin, N-methyl asparagine, SO4. One fragment of γ chain is red, second one white because it is not considered as alpha helix despite identical aminoacid sequence.
The entire oligomer of R-phycoerythrin from Gracilaria chilensis (abg)6 (PDB ID: 1EYX ) R-phycoerythrin 1EYX 2 of 2.gif
The entire oligomer of R-phycoerythrin from Gracilaria chilensis (αβγ)6 (PDB ID: 1EYX )

Spectral characteristics

Absorption (or extinction) and fluorescent (or emission) spectra of phycoerythrin Pycoerythrin spectra.jpg
Absorption (or extinction) and fluorescent (or emission) spectra of phycoerythrin

Absorption peaks in the visible light spectrum are measured at 495 and 545/566 nm, depending on the chromophores bound and the considered organism. A strong emission peak exists at 575 ± 10 nm. (Phycoerythrin absorbs slightly blue-green/yellowish light and emits slightly orange-yellow light.)

PropertyValue
Absorption maximum565 nm
Additional Absorption peak498 nm
Emission maximum573 nm
Extinction Coefficient (ε)1.96×106 M−1 cm−1
Quantum Yield (QY)0.84
Brightness (ε × QY)1.65×106 M−1 cm−1

PEB and DBV bilins in PE545 absorb in the green spectral region too, with maxima at 545 and 569 nm respectively. The fluorescence emission maximum is at 580 nm. [3]

R-Phycoerythrin variations

Excitation and emission profiles for R-Phycoerythrin from two different algae. Common laser excitation wavelengths are also noted. RPEexemComparison.png
Excitation and emission profiles for R-Phycoerythrin from two different algae. Common laser excitation wavelengths are also noted.

As mentioned above, phycoerythrin can be found in a variety of algal species. As such, there can be variation in the efficiency of absorbance and emission of light required for facilitation of photosynthesis. This could be a result of the depth in the water column that a specific alga typically resides and a consequent need for greater or less efficiency of the accessory pigments.

With advances in imaging and detection technology which can avoid rapid photobleaching, protein fluorophores have become a viable and powerful tool for researchers in fields such as microscopy, microarray analysis and Western blotting. In light of this, it may be beneficial for researchers to screen these variable R-phycoerythrins to determine which one is most appropriate for their particular application. Even a small increase in fluorescent efficiency could reduce background noise and lower the rate of false-negative results.

Practical applications

R-Phycoerythrin (also known as PE or R-PE) is useful in the laboratory as a fluorescence-based indicator for the presence of cyanobacteria and for labeling antibodies, most often for flow cytometry. Its also used in microarray assays, ELISAs, and other applications that require high sensitivity but not photostability. [20] Its use is limited in immunofluorescence microscopy due to its rapid photobleaching characteristics. There are also other types of phycoerythrins, such as B-phycoerythrin, which have slightly different spectral properties. B-Phycoerythrin absorbs strongly at about 545 nm (slightly yellowish green) and emits strongly at 572 nm (yellow) instead and could be better suited for some instruments. B-Phycoerythrin may also be less "sticky" than R-phycoerythrin and contributes less to background signal due to nonspecific binding in certain applications.[ citation needed ] However, R-PE is much more commonly available as an antibody conjugate. Phycoerythrin (PE, λA max = 540–570 nm; λF max = 575–590 nm) [8]

R-Phycoerythrin and B-phycoerythrin are among the brightest fluorescent dyes ever identified.

Related Research Articles

<span class="mw-page-title-main">Cryptomonad</span> Subphylum of algae

The cryptomonads are a group of algae, most of which have plastids. They are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10–50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella.

<span class="mw-page-title-main">ATP synthase</span> Enzyme

ATP synthase is an enzyme that catalyzes the formation of the energy storage molecule adenosine triphosphate (ATP) using adenosine diphosphate (ADP) and inorganic phosphate (Pi). ATP synthase is a molecular machine. The overall reaction catalyzed by ATP synthase is:

Cryptomonas is the name-giving genus of the Cryptomonads established by German biologist Christian Gottfried Ehrenberg in 1831. The algae are common in freshwater habitats and brackish water worldwide and often form blooms in greater depths of lakes. The cells are usually brownish or greenish in color and are characteristic of having a slit-like furrow at the anterior. They are not known to produce any toxins. They are used to feed small zooplankton, which is the food source for small fish in fish farms. Many species of Cryptomonas can only be identified by DNA sequencing. Cryptomonas can be found in several marine ecosystems in Australia and South Korea.

<span class="mw-page-title-main">Bacteriorhodopsin</span> Protein used by single-celled organisms

Bacteriorhodopsin (Bop) is a protein used by Archaea, most notably by haloarchaea, a class of the Euryarchaeota. It acts as a proton pump; that is, it captures light energy and uses it to move protons across the membrane out of the cell. The resulting proton gradient is subsequently converted into chemical energy.

<span class="mw-page-title-main">Glucose oxidase</span> Class of enzymes

The glucose oxidase enzyme also known as notatin is an oxidoreductase that catalyses the oxidation of glucose to hydrogen peroxide and D-glucono-δ-lactone. This enzyme is produced by certain species of fungi and insects and displays antibacterial activity when oxygen and glucose are present.

Accessory pigments are light-absorbing compounds, found in photosynthetic organisms, that work in conjunction with chlorophyll a. They include other forms of this pigment, such as chlorophyll b in green algal and vascular ("higher") plant antennae, while other algae may contain chlorophyll c or d. In addition, there are many non-chlorophyll accessory pigments, such as carotenoids or phycobiliproteins, which also absorb light and transfer that light energy to photosystem chlorophyll. Some of these accessory pigments, in particular the carotenoids, also serve to absorb and dissipate excess light energy, or work as antioxidants. The large, physically associated group of chlorophylls and other accessory pigments is sometimes referred to as a pigment bed.

<span class="mw-page-title-main">Phycocyanin</span> Protein complexes in algae

Phycocyanin is a pigment-protein complex from the light-harvesting phycobiliprotein family, along with allophycocyanin and phycoerythrin. It is an accessory pigment to chlorophyll. All phycobiliproteins are water-soluble, so they cannot exist within the membrane like carotenoids can. Instead, phycobiliproteins aggregate to form clusters that adhere to the membrane called phycobilisomes. Phycocyanin is a characteristic light blue color, absorbing orange and red light, particularly near 620 nm, and emits fluorescence at about 650 nm. Allophycocyanin absorbs and emits at longer wavelengths than phycocyanin C or phycocyanin R. Phycocyanins are found in cyanobacteria. Phycobiliproteins have fluorescent properties that are used in immunoassay kits. Phycocyanin is from the Greek phyco meaning “algae” and cyanin is from the English word “cyan", which conventionally means a shade of blue-green and is derived from the Greek “kyanos" which means a somewhat different color: "dark blue". The product phycocyanin, produced by Aphanizomenon flos-aquae and Spirulina, is for example used in the food and beverage industry as the natural coloring agent 'Lina Blue' or 'EXBERRY Shade Blue' and is found in sweets and ice cream. In addition, fluorescence detection of phycocyanin pigments in water samples is a useful method to monitor cyanobacteria biomass.

<span class="mw-page-title-main">Phycobilisome</span> Light-energy harvesting structure in cyanobacteria and red algae

Phycobilisomes are light harvesting antennae of photosystem II in cyanobacteria, red algae and glaucophytes. It was lost in the plastids of green algae / plants (chloroplasts).

<span class="mw-page-title-main">Allophycocyanin</span>

Allophycocyanin is a protein from the light-harvesting phycobiliprotein family, along with phycocyanin, phycoerythrin and phycoerythrocyanin. It is an accessory pigment to chlorophyll. All phycobiliproteins are water-soluble and therefore cannot exist within the membrane like carotenoids, but aggregate, forming clusters that adhere to the membrane called phycobilisomes. Allophycocyanin absorbs and emits red light, and is readily found in Cyanobacteria, and red algae. Phycobilin pigments have fluorescent properties that are used in immunoassay kits. In flow cytometry, it is often abbreviated APC. To be effectively used in applications such as FACS, High-Throughput Screening (HTS) and microscopy, APC needs to be chemically cross-linked.

<span class="mw-page-title-main">Phycobiliprotein</span>

Phycobiliproteins are water-soluble proteins present in cyanobacteria and certain algae. They capture light energy, which is then passed on to chlorophylls during photosynthesis. Phycobiliproteins are formed of a complex between proteins and covalently bound phycobilins that act as chromophores. They are most important constituents of the phycobilisomes.

<span class="mw-page-title-main">Phycoerythrobilin</span> Chemical compound

Phycoerythrobilin is a red phycobilin, i.e. an open tetrapyrrole chromophore found in cyanobacteria and in the chloroplasts of red algae, glaucophytes and some cryptomonads. Phycoerythrobilin is present in the phycobiliprotein phycoerythrin, of which it is the terminal acceptor of energy. The amount of phycoerythrobilin in phycoerythrins varies a lot, depending on the considered organism. In some Rhodophytes and oceanic cyanobacteria, phycoerythrobilin is also present in the phycocyanin, then termed R-phycocyanin. Like all phycobilins, phycoerythrobilin is covalently linked to these phycobiliproteins by a thioether bond.

<span class="mw-page-title-main">Photosynthetic reaction centre</span> Molecular unit responsible for absorbing light in photosynthesis

A photosynthetic reaction center is a complex of several proteins, pigments, and other co-factors that together execute the primary energy conversion reactions of photosynthesis. Molecular excitations, either originating directly from sunlight or transferred as excitation energy via light-harvesting antenna systems, give rise to electron transfer reactions along the path of a series of protein-bound co-factors. These co-factors are light-absorbing molecules (also named chromophores or pigments) such as chlorophyll and pheophytin, as well as quinones. The energy of the photon is used to excite an electron of a pigment. The free energy created is then used, via a chain of nearby electron acceptors, for a transfer of hydrogen atoms (as protons and electrons) from H2O or hydrogen sulfide towards carbon dioxide, eventually producing glucose. These electron transfer steps ultimately result in the conversion of the energy of photons to chemical energy.

A light-harvesting complex consists of a number of chromophores which are complex subunit proteins that may be part of a larger super complex of a photosystem, the functional unit in photosynthesis. It is used by plants and photosynthetic bacteria to collect more of the incoming light than would be captured by the photosynthetic reaction center alone. The light which is captured by the chromophores is capable of exciting molecules from their ground state to a higher energy state, known as the excited state. This excited state does not last very long and is known to be short-lived.

<span class="mw-page-title-main">Succinyl coenzyme A synthetase</span> Class of enzymes

Succinyl coenzyme A synthetase is an enzyme that catalyzes the reversible reaction of succinyl-CoA to succinate. The enzyme facilitates the coupling of this reaction to the formation of a nucleoside triphosphate molecule from an inorganic phosphate molecule and a nucleoside diphosphate molecule. It plays a key role as one of the catalysts involved in the citric acid cycle, a central pathway in cellular metabolism, and it is located within the mitochondrial matrix of a cell.

<span class="mw-page-title-main">Cryptophyceae</span> Class of single-celled organisms

The cryptophyceae are a class of algae, most of which have plastids. About 230 species are known, and they are common in freshwater, and also occur in marine and brackish habitats. Each cell is around 10–50 μm in size and flattened in shape, with an anterior groove or pocket. At the edge of the pocket there are typically two slightly unequal flagella.

Phycoerythrocyanin is a kind of phycobiliprotein, magenta chromoprotein involved in photosynthesis of some Cyanobacteria. This chromoprotein consists of alpha- and beta-subunits, generally aggregated as hexamer. Alpha-phycoerythrocyanin contains a phycoviolobilin, a violet bilin, that covalently attached at Cys-84, and beta-phycoerythrocyanin contains two phycocyanobilins, a blue bilin, that covalently attached at Cys-84 and -155, respectively. Phycoerythrocyanin is similar to phycocyanin, an important component of the light-harvesting complex (phycobilisome) of cyanobacteria and red algae.

<span class="mw-page-title-main">Phycourobilin</span> Chemical compound

Phycourobilin is an orange tetrapyrrole involved in photosynthesis in cyanobacteria and red algae. This chromophore is bound to the phycobiliprotein phycoerythrin, the distal component of the light-harvesting system of cyanobacteria and red algae (phycobilisome).

<span class="mw-page-title-main">Fatty-acyl-CoA synthase</span>

Fatty-acyl-CoA Synthase, or more commonly known as yeast fatty acid synthase, is an enzyme complex responsible for fatty acid biosynthesis, and is of Type I Fatty Acid Synthesis (FAS). Yeast fatty acid synthase plays a pivotal role in fatty acid synthesis. It is a 2.6 MDa barrel shaped complex and is composed of two, unique multi-functional subunits: alpha and beta. Together, the alpha and beta units are arranged in an α6β6 structure. The catalytic activities of this enzyme complex involves a coordination system of enzymatic reactions between the alpha and beta subunits. The enzyme complex therefore consists of six functional centers for fatty acid synthesis.

<span class="mw-page-title-main">Biliprotein</span> Class of pigment proteins in photosynthesising organisms

Biliproteins are pigment protein compounds that are located in photosynthesising organisms such as algae, and sometimes also in certain insects. They refer to any protein that contains a bilin chromophore. In plants and algae, the main function of biliproteins is to make the process of light accumulation required for photosynthesis more efficient; while in insects they play a role in growth and development. Some of their properties: including light-receptivity, light-harvesting and fluorescence have made them suitable for applications in bioimaging and as indicators; while other properties such as anti-oxidation, anti-aging and anti-inflammation in phycobiliproteins have given them potential for use in medicine, cosmetics and food technology. While research on biliproteins dates back as far as 1950, it was hindered due to issues regarding biliprotein structure, lack of methods available for isolating individual biliprotein components, as well as limited information on lyase reactions . Research on biliproteins has also been primarily focused on phycobiliproteins; but advances in technology and methodology, along with the discovery of different types of lyases, has renewed interest in biliprotein research, allowing new opportunities for investigating biliprotein processes such as assembly/disassembly and protein folding.

Alexander Glazer was a professor of the Graduate School in the Department of Molecular and Cell Biology at the University of California, Berkeley. He had a passion for protein chemistry and structure function relationships. He also had a longstanding interest in light-harvesting complexes in cyanobacteria and red algae called phycobilisomes. He had also spent more than 10 years working on the human genome project where he has investigated methods for DNA detection and sequencing which most notably includes the development of fluorescent reagents involved in cell labeling. Most recently, he had focused his studies on issues in environmental sciences. He died on July 18, 2021, in Orinda, California

References

  1. ↑ Basheva D, Moten D, Stoyanov P, Belkinova D, Mladenov R, Teneva I (November 2018). "Content of phycoerythrin, phycocyanin, alophycocyanin and phycoerythrocyanin in some cyanobacterial strains: Applications". Engineering in Life Sciences. 18 (11): 861–866. Bibcode:2018EngLS..18..861B. doi:10.1002/elsc.201800035. PMC   6999198 . PMID   32624879.
  2. 1 2 3 4 5 Ficner R, Huber R (November 1993). "Refined crystal structure of phycoerythrin from Porphyridium cruentum at 0.23-nm resolution and localization of the gamma subunit". European Journal of Biochemistry. 218 (1): 103–106. doi: 10.1111/j.1432-1033.1993.tb18356.x . PMID   8243457.
  3. 1 2 3 van der Weij-De Wit CD, Doust AB, van Stokkum IH, Dekker JP, Wilk KE, Curmi PM, et al. (December 2006). "How energy funnels from the phycoerythrin antenna complex to photosystem I and photosystem II in cryptophyte Rhodomonas CS24 cells" (PDF). The Journal of Physical Chemistry B. 110 (49): 25066–25073. doi:10.1021/jp061546w. PMID   17149931. Archived from the original (PDF) on 30 October 2013.
  4. ↑ Hine, Robert; Martin, Elizabeth, eds. (2015). "Phycoerythrin". A Dictionary of Biology. Oxford University Press. doi:10.1093/acref/9780198714378.001.0001. ISBN   978-0-19-871437-8 . Retrieved 2021-11-27– via login.aurarialibrary.idm.oclc.org.
  5. ↑ Dammeyer T, Frankenberg-Dinkel N (September 2006). "Insights into phycoerythrobilin biosynthesis point toward metabolic channeling". The Journal of Biological Chemistry. 281 (37): 27081–27089. doi: 10.1074/jbc.M605154200 . PMID   16857683.
  6. ↑ Six C, Thomas JC, Garczarek L, Ostrowski M, Dufresne A, Blot N, et al. (2007). "Diversity and evolution of phycobilisomes in marine Synechococcus spp.: a comparative genomics study". Genome Biology. 8 (12): R259. doi: 10.1186/gb-2007-8-12-r259 . PMC   2246261 . PMID   18062815.
  7. ↑ Glazer AN (1985). "Light harvesting by phycobilisomes". Annual Review of Biophysics and Biophysical Chemistry. 14: 47–77. doi:10.1146/annurev.bb.14.060185.000403. PMID   3924069.
  8. 1 2 Sonani RR, Rastogi RP, Patel R, Madamwar D (February 2016). "Recent advances in production, purification and applications of phycobiliproteins". World Journal of Biological Chemistry. 7 (1): 100–109. doi: 10.4331/wjbc.v7.i1.100 . PMC   4768114 . PMID   26981199.
  9. 1 2 Camara-Artigas, A. (2011-12-16). "Crystal Structure of the B-phycoerythrin from the red algae Porphyridium cruentum at pH8". RCSB Protein Data Bank (PDB). doi:10.2210/pdb3v57/pdb. PDB ID: 3V57. Retrieved 12 October 2012.{{cite journal}}: Cite journal requires |journal= (help)
  10. 1 2 Camara-Artigas A, Bacarizo J, Andujar-Sanchez M, Ortiz-Salmeron E, Mesa-Valle C, Cuadri C, et al. (October 2012). "pH-dependent structural conformations of B-phycoerythrin from Porphyridium cruentum". The FEBS Journal. 279 (19): 3680–3691. doi:10.1111/j.1742-4658.2012.08730.x. PMID   22863205. S2CID   31253970. PDB ID: 3V57.
  11. 1 2 3 4 Image created with RasTop (Molecular Visualization Software).
  12. ↑ "Protein Data Bank". RCSB Protein Data Bank (PDB). Archived from the original on 28 August 2008. Retrieved 12 October 2012.
  13. ↑ Doust AB, Marai CN, Harrop SJ, Wilk KE, Curmi PM, Scholes GD (2004-09-16). "High resolution crystal structure of phycoerythrin 545 from the marine cryptophyte rhodomonas CS24". RCSB Protein Data Bank (PDB). doi:10.2210/pdb1xg0/pdb. PDB ID: 1XG0. Retrieved 11 October 2012.{{cite journal}}: Cite journal requires |journal= (help)
  14. ↑ Doust AB, Marai CN, Harrop SJ, Wilk KE, Curmi PM, Scholes GD (November 2004). "Developing a structure-function model for the cryptophyte phycoerythrin 545 using ultrahigh resolution crystallography and ultrafast laser spectroscopy". Journal of Molecular Biology. 344 (1): 135–153. doi:10.1016/j.jmb.2004.09.044. PMID   15504407. PDB ID: 1XG0.
  15. 1 2 3 4 Contreras-Martel C, Martinez-Oyanedel J, Bunster M, Legrand P, Piras C, Vernede X, Fontecilla-Camps JC (2000-05-09). "Crystal structure of R-phycoerythrin at 2.2 angstroms". RCSB Protein Data Bank (PDB). doi:10.2210/pdb1eyx/pdb. PDB ID: 1EYX. Retrieved 11 October 2012.{{cite journal}}: Cite journal requires |journal= (help)
  16. 1 2 3 4 Contreras-Martel C, Martinez-Oyanedel J, Bunster M, Legrand P, Piras C, Vernede X, Fontecilla-Camps JC (January 2001). "Crystallization and 2.2 A resolution structure of R-phycoerythrin from Gracilaria chilensis: a case of perfect hemihedral twinning". Acta Crystallographica. Section D, Biological Crystallography. 57 (Pt 1): 52–60. doi:10.1107/S0907444900015274. PMID   11134927. S2CID   216930. PDB ID: 1EYX.
  17. ↑ Apt KE, Hoffman NE, Grossman AR (August 1993). "The gamma subunit of R-phycoerythrin and its possible mode of transport into the plastid of red algae". The Journal of Biological Chemistry. 268 (22): 16208–16215. doi: 10.1016/S0021-9258(19)85407-8 . PMID   8344905.
  18. ↑ Ritter S, Hiller RG, Wrench PM, Welte W, Diederichs K (1999-01-29). "Crystal structure of a phycourobilin-containing phycoerythrin". doi:10.2210/pdb1b8d/pdb. PDB ID: 1B8D.{{cite journal}}: Cite journal requires |journal= (help)
  19. ↑ Ritter S, Hiller RG, Wrench PM, Welte W, Diederichs K (June 1999). "Crystal structure of a phycourobilin-containing phycoerythrin at 1.90-A resolution". Journal of Structural Biology. 126 (2): 86–97. doi:10.1006/jsbi.1999.4106. PMID   10388620. PDB ID: 1B8D.
  20. ↑ "R-phycoerythrin (R-PE) - US". www.thermofisher.com. Retrieved 2021-12-11.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.