scholarly journals Bile pigment synthesis in plants. Incorporation of haem into phycocyanobilin and phycobiliproteins in Cyanidium caldarium

1981 ◽  
Vol 194 (1) ◽  
pp. 137-147 ◽  
Author(s):  
S B Brown ◽  
J A Holroyd ◽  
R F Troxler ◽  
G D Offner
Keyword(s):  
Chlorophyll A ◽  
Protoporphyrin Ix ◽  
Bile Pigment ◽  
Cyanidium Caldarium ◽  
Pigment Synthesis ◽  
14C Labelling

A procedure was developed whereby haem was taken up by dark-grown cells of the unicellular rhodophyte Cyanidium caldarium. These cells were subsequently incubated either in the dark with 5-aminolaevulinate, which results in excretion of phycocyanobilin into the suspending medium or incubated in the light, which results in synthesis and accumulation of phycocyanin and chlorophyll a within the cells. Phycocyanobilin was isolated from phycocyanin by cleavage from apoprotein in methanol. Phycocyanobilin prepared from phycocyanin or excreted from cells given 5-aminolaevulinate was methylated and purified by t.l.c. By using 14C labelling either in the haem or in 5-aminolaevulinate administered, haem incorporation into phycocyanobilin was demonstrated in both dark and light systems. Since chlorophyll a synthesized in the light in the presence of labelled haem contained no radioactivity, it was clear that haem was directly incorporated into phycocyanobilin and not first converted into protoporphyrin IX. These results clearly demonstrate phycocyanobilin synthesis via haem and not via magnesium protoporphyrin IX as has also been postulated.

scholarly journals Phycocyanobilin synthesis in the unicellular rhodophyte Cyanidium caldarium

1978 ◽  
Vol 172 (3) ◽  
pp. 569-576 ◽  
Author(s):  
R F Troxler ◽  
P Kelly ◽  
S B Brown
Keyword(s):  
Absorption Spectrum ◽  
Mass Spectrum ◽  
Electronic Absorption ◽  
Bile Pigment ◽  
Cyanidium Caldarium ◽  
Pigment Synthesis ◽  
Structural Identity ◽  
Electron Impact Mass ◽  
Impact Mass

Light is required for synthesis of the accessory photosynethetic pigment phycocyanin in cells of the unicellular rhodophyte Cyanidium caldarium. Phycocyanin is a conjugated protein composed of polypeptide subunits to which the light-absorbing bile pigment chromophore phycocyanobilin is covalently attached. Dark-grown cells of C. caldarium are unable to make phycocyanin, but when incubated in the dark with 5-aminolaevulinate the cells synthesize and excrete a protein-free phycobilin (algal bile pigment) into the suspending medium. The electronic absorption spectrum, electron impact mass spectrum, chromatographic properties and imide products obtained after chronic acid degradation of the excreted phycobilin were identical with those of phycocyanobilin cleaved from phycocyanin in boiling methanol. This establishes the structural identity between the excreted phycobilin, which is the end product of bile-pigment synthesis in vivo, and the chromophore cleaved from phycocyanin in boiling methanol. The significance of the structure of the excreted phycobilin with respect to the events surrounding the assembly of the phycocyanin molecule in vivo is discussed.

scholarly journals Mechanism of bile-pigment synthesis in algae. 18O incorporation into phycocyanobilin in the unicellular rhodophyte, Cyanidium caldarium

1980 ◽  
Vol 190 (2) ◽  
pp. 445-449 ◽  
Author(s):  
S B Brown ◽  
A J Holroyd ◽  
R F Troxler
Keyword(s):  
Gas Phase ◽  
Bile Pigment ◽  
Cyanidium Caldarium ◽  
Pigment Synthesis ◽  
Slow Exchange ◽  
Oxygen Atoms

The origin of the lactam oxygen atoms of phycocyanobilin from Cyanidium caldarium was studied using 18O labelling. By inhibiting photosynthesis, a high 18O enrichment was maintained in the gas phase and the resulting incorporation of label showed that the lactam oxygen atoms were derived from two oxygen molecules. Slow exchange of these oxygen atoms with water was demonstrated directly by using H218O.

Biliverdin IX α, Intermediate and End Product of Tetrapyrolle Biosynthesis

1982 ◽  
Vol 37 (11-12) ◽  
pp. 1057-1063 ◽  
Author(s):  
Hans-Peter Köst ◽  
Eva Benedikt
Keyword(s):  
Aminolevulinic Acid ◽  
Chromic Acid ◽  
Protoporphyrin Ix ◽  
Chloroform Extract ◽  
Cyanidium Caldarium ◽  
Green Pigment ◽  
Acid Degradation ◽  
Turdus Merula ◽  
Egg Shells ◽  
Biliverdin Ix

Abstract Dark-grown cells of the unicellular rhodophyte Cyanidium caldarium were incubated with 17 mmol/l 5-aminolevulinic acid in the dark. The excreted pigments were extracted with chloroform and butanol. The presence of biliverdin IX α in the chloroform-extract (besides phycocyanobilin and other pigments) was demonstrated using TLC, HPLC and chromic acid degradation. A pathway leading to phycocyanobilin is discussed. A green pigment from egg shells of Turdus merula (black bird) was also identified as biliverdin IX α with small amounts of protoporphyrin IX, using the same methods as above.

scholarly journals Photosystem Disorder Could be the Key Cause for the Formation of Albino Leaf Phenotype in Pecan

2020 ◽  
Vol 21 (17) ◽  
pp. 6137
Author(s):  
Ji-Yu Zhang ◽  
Tao Wang ◽  
Zhan-Hui Jia ◽  
Zhong-Ren Guo ◽  
Yong-Zhi Liu ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Molecular Mechanisms ◽  
Chlorophyll Biosynthesis ◽  
Protoporphyrin Ix ◽  
Photosynthetic Electron Transport ◽  
Chlorophyll Degradation ◽  
Pheophorbide A ◽  
Leaf Phenotype ◽  
Photosynthesis Pathway ◽  
Almost All

Pecan is one of the most famous nut species in the world. The phenotype of mutants with albino leaves was found in the process of seeding pecan, providing ideal material for the study of the molecular mechanisms leading to the chlorina phenotype in plants. Both chlorophyll a and chlorophyll b contents in albino leaves (ALs) were significantly lower than those in green leaves (GLs). A total of 5171 differentially expression genes (DEGs) were identified in the comparison of ALs vs. GLs using high-throughput transcriptome sequencing; 2216 DEGs (42.85%) were upregulated and 2955 DEGs (57.15%) were downregulated. The expressions of genes related to chlorophyll biosynthesis (HEMA1, encoding glutamyl-tRNA reductase; ChlH, encoding Mg-protoporphyrin IX chelatase (Mg-chelatase) H subunit; CRD, encoding Mg-protoporphyrin IX monomethylester cyclase; POR, encoding protochlorophyllide reductase) in ALs were significantly lower than those in GLs. However, the expressions of genes related to chlorophyll degradation (PAO, encoding pheophorbide a oxygenase) in ALs were significantly higher than those in GLs, indicating that disturbance of chlorophyll a biosynthesis and intensification of chlorophyll degradation lead to the absence of chlorophyll in ALs of pecan. A total of 72 DEGs associated with photosynthesis pathway were identified in ALs compared to GLs, including photosystem I (15), photosystem II (19), cytochrome b6-f complex (3), photosynthetic electron transport (6), F-type ATPase (7), and photosynthesis-antenna proteins (22). Moreover, almost all the genes (68) mapped in the photosynthesis pathway showed decreased expression in ALs compared to GLs, declaring that the photosynthetic system embedded within the thylakoid membrane of chloroplast was disturbed in ALs of pecan. This study provides a theoretical basis for elucidating the molecular mechanism underlying the phenotype of chlorina seedlings of pecan.

Pyrazolinyl and cyclopropyl derivatives of protoporphyrin IX and chlorins related to chlorophyll a

Tetrahedron ◽  
2003 ◽  
Vol 59 (4) ◽  
pp. 499-504 ◽  
Author(s):  
Andrei N Kozyrev ◽  
James L Alderfer ◽  
Byron C Robinson
Keyword(s):  
Chlorophyll A ◽  
Protoporphyrin Ix ◽  
Derivatives Of

The chemistry of pyrrolic compounds. XIV. meso-Hydroxyprotoporphyrin IX and its derivatives

1970 ◽  
Vol 23 (12) ◽  
pp. 2477 ◽  
Author(s):  
PS Clezy ◽  
AJ Liepa
Keyword(s):  
Protoporphyrin Ix ◽  
Bile Pigment ◽  
General Properties ◽  
Biliverdin Ix ◽  
Hydrolysis Of ◽  
Derivatives Of ◽  
Benzoate Derivatives

The preparation of the acetate and benzoate derivatives of �-hydroxy-protoporphyrin IX is described and the hydrolysis of these enolic esters examined. The general properties of these porphyrins are discussed together with the oxidation of this system to a bile pigment identical with biliverdin IX�: with regard to spectroscopic and chromatographic characteristics.

scholarly journals The effect of gabaculine on tetrapyrrole biosynthesis and heterotrophic growth in Cyanidium caldarium

1988 ◽  
Vol 254 (3) ◽  
pp. 907-910 ◽  
Author(s):  
J D Houghton ◽  
L Turner ◽  
S B Brown
Keyword(s):  
Chlorophyll Synthesis ◽  
Similar Rate ◽  
Red Alga ◽  
Heterotrophic Growth ◽  
Tetrapyrrole Biosynthesis ◽  
Cyanidium Caldarium ◽  
Pigment Synthesis ◽  
Subsequent Exposure ◽  
Light Inhibition ◽  
Lag Period

Pigment synthesis in four strains of the unicellular red alga Cyanidium caldarium with different pigment-synthesizing patterns was inhibited in the presence of gabaculine (3-amino-2,3-dihydrobenzoic acid). Parallel inhibition of light-induced chlorophyll and phycocyanin synthesis was observed in strain III-D-2, which only synthesizes pigments in the light. Similar parallel inhibition was observed in the dark in mutant CPD, which is able to synthesize chlorophyll and phycocyanin in the absence of light. Inhibition of pigment synthesis in all strains was overcome by addition of 5-aminolaevulinic acid. Inhibition of phycocyanin synthesis in mutant GGB (unable to synthesize chlorophyll) and inhibition of chlorophyll synthesis in mutant III-C (unable to synthesize phycocyanin) were also observed. Gabaculine also inhibited the heterotrophic growth of C. caldarium in the dark. However, inhibition was overcome after an extended lag period, following which cell growth proceeded at a similar rate to that of control cells not exposed to gabaculine. Heterotrophic growth in cells pre-exposed to gabaculine was not inhibited by subsequent exposure. Possible mechanisms for this adaptation are discussed.

Chlorophyll a biosynthesis

1976 ◽  
Vol 273 (924) ◽  
pp. 207-225 ◽  
Keyword(s):  
Chlorophyll A ◽  
Chlorophyll Biosynthesis ◽  
Protoporphyrin Ix ◽  
Chlorophyll Synthesis ◽  
Synthesis Reaction ◽  
Etiolated Leaves ◽  
Regulatory Aspects ◽  
Vinyl Group ◽  
Chlorophyll A Biosynthesis ◽  
Monomethyl Ester

Protoporphyrin IX is believed to be an intermediate common to both haem and chlorophyll biosynthesis. The pathway specific to chlorophyll starts with magnesium protoporphyrin and its monomethyl ester. Two routes have been proposed for conversion of the latter compound to protochlorophyllide: A, formation of the isocyclic ring followed by reduction of the 4-vinyl group, or B, reduction of the 4-vinyl group followed by formation of the isocyclic ring. Membranes prepared from isolated barley etioplasts are found to convert magnesium 2,4-divinylphaeoporphyrin a 5 monomethyl ester to chlorophyllide a at a rate equal to that of chlorophyll synthesis in intact leaves: this result supports route A. NADPH is necessary to maintain the two successive reductive steps: reduction of the 4-vinyl group and then the photoreduction of ring IV to yield chlorophyllide. The prohaem content of etiolated leaves does not increase during the phase of active chlorophyll synthesis although evidence is presented that suggests that the ALA synthesis reaction that regulates chlorophyll synthesis is common to both pathways. This and other regulatory aspects are discussed.

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