Bile Pigment Formation in Plants

Troxler, Robert F.; Brown, Anne S.; Lester, Roger; White, Peter

doi:10.1126/science.167.3915.192

Cited by 36 publications

(16 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ratio of the specific radioactivity of phycoerythrobilin to that of CO synthesized from ALA in P. cruentum cells is what would be predicted if these compounds arose directly from the protoporphyrin IX skeleton of a metalloporphyrin precursor (Table II; experiment II). This conclusion is consistent with the data on specific radioactivity ratios of phycocyanobilin and CO made from ALA-5-4C in cells of the green alga, Cyanidium caldarium (31). It has been observed that metal-free protoporphyrin IX is converted slowly and inefficiently to bile pigment in mammals (7), in contrast to hemoglobin or hematin which are rapidly and quantitatively converted to CO and bilirubin in vivo (2,11) and in vitro (26,27).…”

Section: Discussionsupporting

confidence: 88%

See 1 more Smart Citation

Formation of Carbon Monoxide and Bile Pigment in Red and Blue-Green Algae

Troxler

Dokos²

1973

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

Five blue-green and one red algal species produced carbon monoxide during photosynthetic growth. The blue-green algae synthesized CO and phycocyanobilin in equimolar quantities at identical rates. The red alga, Porphyridium cruentum, incorporated z-aminolevulinic acid-5-14C into phycoerythrobilin and CO. The ratio of the specific radioactivity of phycoerythrobilin to that of CO, and the kinetics and stoichiometry of phycocyanobilin and CO formation suggest that linear tetrapyrroles in plants are derived by the porphyrin pathway via the intermediate formation of heme. The similarity between bile pigment production in algae and in mammalian systems is discussed.Phycocyanobilin and phycoerythrobilin are linear tetrapyrroles covalently linked to apoproteins occurring in the photosynthetic apparatus of red, blue-green, and cryptomonad algae (17). These compounds are structurally related to bilirubin, the principal mammalian bile pigment derived from hemoglobin in senescent erythrocytes (1,14, 18,19). It is known that CO is produced endogenously in normal man (24), and that approximately 1 mole of CO is produced per mole of heme catabolized (2, 1 1). CO formation has been described in algae (6,12,15), in fungi (23, 33), and in higher plants (22,34). CO produced in the fungus, Aspergillus niger, has been shown to arise from the breakdown of rutin to phloroglucinol and protocatechuic acid (23). Nevertheless, in most reports concerning algae and higher plants, the metabolic origin of CO has not been established. We have shown that in the green algae, Cyanidium caldarium, CO is a by-product of phycocyanobilin formation (31). The present paper describes some quantitative and kinetic parameters of CO and bile pigment formation in five species of blue-green algae and in the red alga, Porphyridium cruentum.

show abstract

Section: Discussionsupporting

confidence: 88%

“…It has been shown that the CO evolved by cells of the alga, C. caldarium, was a by-product of phycocyanobilin formation (31). However, the origin of CO produced by other algae and by higher plants has yet to be established.…”

Section: Discussionmentioning

confidence: 99%

Formation of Carbon Monoxide and Bile Pigment in Red and Blue-Green Algae

Troxler

Dokos²

1973

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…mmole) were added. Previous results have shown that C. caldarium cells administered ALA-5-"C2 synthesized equimolar quantities of "CO and phycocyanobilin-"C (15). Theoretically, 8 moles of ALA-5-w"C are required for synthesis of 1 mole of heme, which would contain 4 labeled carbon atoms in the pyrrole rings, and 4 labeled carbon atoms in the methyne bridges.…”

Section: Cells In the Lightmentioning

confidence: 98%

“…The specific radioactivity of phycocyanobilin was divided by 7 so it could be compared directly to that of CO. The specific radioactivity of phycocyanobilin was determined from spectral and radiochemical measurements as described previously (15). 1 Represents CO present in the reservoir and in the dead volume of the system consisting of rubber tubing and the gas above the cell suspension in the fermentator tank.…”

Section: Cells In the Lightmentioning

confidence: 99%

“…It is now well established that during the breakdown of hemoglobin in senescent erythrocytes in humans, the heme ring is cleaved by removal of the a-methyne bridge carbon which is then oxidized to CO with the concomitant formation of bile pigment and iron (13). Recent work in this laboratory has shown that during the formation of phycocyanobilin, equimolar quantities of CO are similarly produced (15). Although CO can be measured by mass spectrometry (2), by gas chromatography (5), or by nondispersive infrared analysis (1), these methods require the availability of costly equipment and preclude certain kinds of metabolic experimentation on CO biosynthesis from radiolabeled precursors.…”

mentioning

confidence: 99%

See 1 more Smart Citation

An Inexpensive Technique for Measuring Carbon Monoxide Formation in Plants

Troxler

1971

Plant Physiol.

Self Cite

View full text Add to dashboard Cite

Biological production of carbon monoxide has been reported in algae (3, 7), in fungi (16), in higher plants (10,18), in siphonophores (19), and in man (12,17). It is now well established that during the breakdown of hemoglobin in senescent erythrocytes in humans, the heme ring is cleaved by removal of the a-methyne bridge carbon which is then oxidized to CO with the concomitant formation of bile pigment and iron (13). Recent work in this laboratory has shown that during the formation of phycocyanobilin, equimolar quantities of CO are similarly produced (15). Although CO can be measured by mass spectrometry (2), by gas chromatography (5), or by nondispersive infrared analysis (1), these methods require the availability of costly equipment and preclude certain kinds of metabolic experimentation on CO biosynthesis from radiolabeled precursors. The present paper describes, therefore, an inexpensive method for determining biological CO production in algae, which is generally adaptable to studies on CO formation in plants. Figure 1A. At 4-to 15-hr intervals, estimates of phycocyanobilin synthesized in the suspension (9) and of CO present in the gas reservoir were made. MATERIALS AND METHODSCO Measurement. CO accumulated in the gas reservoir was passed through the train assembly shown in Figure lB RESULTS AND DISCUSSION The train shown in Figure 1B is designed to measure CO as catalytically derived CO2 after removal of CO2 (not derived) from the sample gas. In calibration experiments, 22.3 and 44.6 t-moles of CO, representing 0.5 and 1.0 ml of the pure gas, were injected with a tuberculin syringe into 95% 02-5% CO., contained in a 2-liter glass suction flask. The sample gas was then forced through the train by displacement from the flask with water. Under these conditions, recoveries of CO as derived CO2 exceeded 95% (Table I). Titration of alkali in the test trap (VI) preceding the Hopcalite catalyst (VIII) revealed that bicarbonate was lacking, which shows that the Baralyme, Ascarite, and NaOH absorbers had efficiently removed CO. from the gas sample.For calibration of the train with "CO standards (New England Nuclear, Boston, Mass.; 4.5 mc/mmole) radiolabeled CO was mixed with carrier gas as above and passed through the train. The disintegrations per minute in derived "CO2 were determined by driving "C-labeled bicarbonate from solution after titration of the residual alkali in the terminal traps (IX) to pH 8.5. "CO.. was collected in 5 ml of ethanolamine-methoxvethanol (2:1) and counted in 15 ml of toluene-methoxyethanol (2:1) containing 4 g/liter of 2,5-bis-2(tertiarybutylbenzoxazolyl)-,B-thiophene (Packard Instrument Co., Downers Grove. Ill.). All counting was done in a Tri-Carb liquid scintillation spectrometer. and the quench in each vial was determined by the addition of toluene-"C internal standard.The recovery of 33.0 and 34.0 1cmoles of "CO placed in 2 liters of 95%-0-5%o CO. and passed through the train was 376 www.plantphysiol.org on May 8, 2018 -Published by Downloaded from

show abstract

Die Reaktivität des Porphyrinliganden

Fuhrhop¹

1974

Angewandte Chemie

View full text Add to dashboard Cite

Die physikalischen Eigenschaften und die chemische Reaktivität des Porphyrin‐Makrocyclus, dessen Bildung mit einem einfachen statistischen Argument rationalisiert werden kann, sind in mannigfacher Weise mit denen der aromatischen Kohlenwasserstoffe verwandt. Die Reaktivität des Porphyrinliganden in seinen Metallkomplexen wird durch den unterschiedlich ausgeprägten induktiven Effekt der jeweiligen zentralen Metall‐Ionen auf das konjugierte π‐Elektronensystem in weiten Grenzen variiert. Einelektronenreaktionen, Phlorinbildungen durch Addition von Wasserstoff oder Sauerstoff an die Methinbrücken sowie die Bildung von π‐Komplexen stehen dabei im Vordergrund. Die biochemische Reaktivität des Porphyrinliganden entspricht weitgehend seiner in‐vitro‐Chemie.

show abstract

Bile Pigment Formation in Plants

Cited by 36 publications

References 5 publications

Formation of Carbon Monoxide and Bile Pigment in Red and Blue-Green Algae

Formation of Carbon Monoxide and Bile Pigment in Red and Blue-Green Algae

An Inexpensive Technique for Measuring Carbon Monoxide Formation in Plants

Die Reaktivität des Porphyrinliganden

Contact Info

Product

Resources

About