PHYTOCHROME MODELS, PART 9. CONFORMATION SELECTIVITY OF THE PHOTOCYCLIZATION OF THE BILIVERDIN IX γ and IX δ DIMETHYL ESTERS

1985 ◽  
Vol 41 (3) ◽  
pp. 237-246 ◽  
Author(s):  
Silvia E. Braslavsky ◽  
Hussain Al-Ekabi ◽  
Christian Petrier ◽  
Kurt Schaffner
Keyword(s):  
Phytochrome Models ◽  
Biliverdin Ix

scholarly journals Recombinant Production of Biliverdin IXβ and δ Isomers in the T7 Promoter Compatible Escherichia coli Nissle

2021 ◽  
Vol 12 ◽  
Author(s):  
Elizabeth A. Robinson ◽  
Nicole Frankenberg-Dinkel ◽  
Fengtian Xue ◽  
Angela Wilks
Keyword(s):  
Heme Oxygenase ◽  
Chemical Oxidation ◽  
Heme Biosynthesis ◽  
T7 Promoter ◽  
E Coli ◽  
Recombinant Production ◽  
Alternative Approaches ◽  
Biliverdin Ix ◽  
Scalable Production ◽  
Escherichia Coli Nissle

The ability to obtain purified biliverdin IX (BVIX) isomers other than the commercially available BVIXα is limited due to the low yields obtained by the chemical coupled oxidation of heme. Chemical oxidation requires toxic chemicals, has very poor BVIX yields (<0.05%), and is not conducive to scalable production. Alternative approaches utilizing recombinant E. coli BL21 expressing a cyanobacterial heme oxygenase have been employed for the production BVIXα, but yields are limited by the rate of endogenous heme biosynthesis. Furthermore, the emerging roles of BVIXβ and BVIXδ in biology and their lack of commercial availability has led to a need for an efficient and scalable method with the flexibility to produce all three physiologically relevant BVIX isomers. Herein, we have taken advantage of an optimized non-pathogenic E. coli Nissle (EcN(T7)) strain that encodes an endogenous heme transporter and an integrated T7 polymerase gene. Protein production of the Pseudomonas aeruginosa BVIXβ and BVIXδ selective heme oxygenase (HemO) or its BVIXα producing mutant (HemOα) in the EcN(T7) strain provides a scalable method to obtain all three isomers, that is not limited by the rate of endogenous heme biosynthesis, due to the natural ability of EcN(T7) to transport extracellular heme. Additionally, we have optimized our previous LC-MS/MS protocol for semi-preparative separation and validation of the BVIX isomers. Utilizing this new methodology for scalable production and separation we have increased the yields of the BVIXβ and -δ isomers >300-fold when compared to the chemical oxidation of heme.

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.

Linear tetrapyrroles as functional pigments in chemistry and biology

2004 ◽  
Vol 08 (03) ◽  
pp. 226-237 ◽  
Author(s):  
Tadashi Mizutani ◽  
Shigeyuki Yagi
Keyword(s):  
Conformational Changes ◽  
Materials Science ◽  
Redox Activity ◽  
Helical Conformation ◽  
Biological Functions ◽  
Experimental Conditions ◽  
Chiral Structure ◽  
Biliverdin Ix ◽  
Linear Tetrapyrroles ◽  
Single Bonds

1,19,21,24-tetrahydro-1,19-bilindione is the framework of pigments frequently found in nature, which includes biliverdin IX α, phytochromobilin and phycocyanobilin. 1,19-bilindiones have unique features such as (1) photochemical and thermal cis-trans isomerization, (2) excited energy transfer, (3) chiroptical properties due to the cyclic helical conformation, (4) redox activity, (5) coordination to various metals, and (6) reconstitution to proteins. 1,19-bilindione can adopt a number of conformations since it has exocyclic three double bonds and three single bonds that are rotatable thermally and photochemically. In solution, biliverdin and phycocyanobilin adopt a cyclic helical ZZZ, syn, syn, syn conformation, but other conformations are stabilized depending on the experimental conditions and substituents on the bilin framework. The conformational changes in 1,19-bilindiones are related to the biological functions of a photoreceptor protein, phytochrome. Structural and conformational studies of bilindiones are summarized both in solution and in protein. The conformational changes of bilins can be used for other functions such as a chirality sensor. The bilindiones and the zinc complexes of bilindiones can be employed as a chirality sensor due to the helically chiral structure and the dynamics of racemization of enantiomers. In this paper, we discuss the conformational equilibria and dynamics of bilindiones and its implications in photobiology and materials science.

scholarly journals Characterization of an NADH-dependent haem-degrading system in ox heart mitochondria

1987 ◽  
Vol 246 (2) ◽  
pp. 467-474 ◽  
Author(s):  
R K Kutty ◽  
M D Maines
Keyword(s):  
Cytochrome C ◽  
Complex I ◽  
Effective Interaction ◽  
Heart Mitochondria ◽  
Nadh:Ubiquinone Oxidoreductase ◽  
Reaction Products ◽  
Degradation Activity ◽  
Haem Oxygenase ◽  
Biliverdin Ix ◽  
Degrading System

We report the identification of an NADH-dependent haem-degrading system in ox heart mitochondria. The activity was localized to the mitochondrial inner membrane, specifically associated with complex I (NADH:ubiquinone oxidoreductase). The mitochondrial NADH-dependent haem-degradation activity was highly effective and displayed a rate nearly 60% higher than that of the microsomal activity. The following observations suggested the enzymic nature of the activity: (i) haem degradation by complex I did not proceed upon exposure to elevated temperature and extremes of pH; (ii) it displayed substrate specificity; (iii) it was inhibited by a substrate analogue; and (iv) it showed a cofactor requirement. Moreover, the activity was distinctly different from the ascorbate-mediated haem-degradation activity. Also, complex I differed from the microsomal NADPH:cytochrome c (P-450) reductase inasmuch as the formation of an effective interaction with the microsomal haem oxygenase could not be detected. Addition of purified haem oxygenase to complex I neither influenced the rate of haem degradation nor resulted in the formation of biliverdin IX alpha. In contrast, addition of haem oxygenase to NADPH:cytochrome c (P-450) reductase enhanced the rate of haem degradation by nearly 8-fold, and more than 60% of the degraded haem could be accounted for as biliverdin IX alpha. The haem-degrading activity of complex I appeared to involve the activity of H2O2, as the reaction was inhibited by nearly 90% by catalase, and propentdyopents were detected as reaction products. Intact haemoproteins such as cytochrome c and myoglobin were not effective substrates. However, the haem undecapeptide of cytochrome c was degraded at a rate equal to that observed for haem. Haematohaem was degraded at a rate 50% lower than that observed for haem. It is suggested that the NADH-dependent haem-degradation system may have a biological role in the regulation of the concentration of respiratory haemoproteins and the disposition of the aberrant forms of the mitochondrial haemoproteins.

scholarly journals Homologues of Neisserial Heme Oxygenase in Gram-Negative Bacteria: Degradation of Heme by the Product of thepigA Gene of Pseudomonas aeruginosa

2001 ◽  
Vol 183 (21) ◽  
pp. 6394-6403 ◽  
Author(s):  
Melanie Ratliff ◽  
Wenming Zhu ◽  
Rahul Deshmukh ◽  
Angela Wilks ◽  
Igor Stojiljkovic
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Heme Oxygenase ◽  
High Performance ◽  
Visible Spectrum ◽  
Inducible Promoter ◽  
Major Product ◽  
Gene Encoding ◽  
Heme Oxygenases ◽  
Chromatography Analysis ◽  
Biliverdin Ix

ABSTRACT The oxidative cleavage of heme to release iron is a mechanism by which some bacterial pathogens can utilize heme as an iron source. ThepigA gene of Pseudomonas aeruginosa is shown to encode a heme oxygenase protein, which was identified in the genome sequence by its significant homology (37%) with HemO ofNeisseria meningitidis. When the gene encoding the neisserial heme oxygenase, hemO, was replaced withpigA, we demonstrated that pigA could functionally replace hemO and allow for heme utilization by neisseriae. Furthermore, when pigA was disrupted by cassette mutagenesis in P. aeruginosa, heme utilization was defective in iron-poor media supplemented with heme. This defect could be restored both by the addition of exogenous FeSO4, indicating that the mutant did not have a defect in iron metabolism, and by in trans complementation with pigA from a plasmid with an inducible promoter. The PigA protein was purified by ion-exchange chromotography. The UV-visible spectrum of PigA reconstituted with heme showed characteristics previously reported for other bacterial and mammalian heme oxygenases. The heme-PigA complex could be converted to ferric biliverdin in the presence of ascorbate, demonstrating the need for an exogenous reductant. Acidification and high-performance liquid chromatography analysis of the ascorbate reduction products identified a major product of biliverdin IX-β. This differs from the previously characterized heme oxygenases in which biliverdin IX-α is the typical product. We conclude that PigA is a heme oxygenase and may represent a class of these enzymes with novel regiospecificity.

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 Enzymic conversion of α-oxyprotohaem IX into biliverdin IXα by haem oxygenase

1990 ◽  
Vol 270 (3) ◽  
pp. 659-664 ◽  
Author(s):  
T Yoshinaga ◽  
Y Sudo ◽  
S Sano
Keyword(s):  
Cytochrome C ◽  
Kinetic Study ◽  
Maximum Velocity ◽  
Incubation Mixture ◽  
Biliverdin Reductase ◽  
Cytochrome C Reductase ◽  
Nadph Cytochrome ◽  
Haem Oxygenase ◽  
Biliverdin Ix ◽  
Nadph Cytochrome C Reductase

Conversion of four isomers of meso-oxyprotohaem IX into the corresponding biliverdin IX was attempted with a reconstituted haem oxygenase system in the presence of NADPH-cytochrome c reductase and NADPH. Only the alpha-isomer of meso-oxyprotohaem IX was converted effectively into biliverdin IX alpha, which was further reduced to bilirubin IX alpha by biliverdin reductase. Only trace amounts of biliverdins IX beta, IX gamma and IX delta were respectively formed from the incubation mixture of the corresponding oxyprotohaemin IX isomers with the complete haem oxygenase system under the same conditions. In a kinetic study, the Km for alpha-meso-oxyprotohaem IX was 3.6 microM, which was 2-fold higher than that for protohaem IX. The maximum velocity (Vmax.) of the conversion of alpha-meso-oxyprotohaem IX into biliverdin IX alpha was twice as fast as that of protohaem IX. These results demonstrate that alpha-meso-oxyprotohaem IX is an intermediate of haem degradation and it was converted stereospecifically into biliverdin IX alpha via verdohaem IX alpha.

scholarly journals Synthesis and separation by thin-layer chromatography of bilirubin-IX isomers. Their identification as tetrapyrroles and dipyrrolic ethyl anthranilate azo derivatives

1976 ◽  
Vol 155 (2) ◽  
pp. 405-417 ◽  
Author(s):  
N Blanckaert ◽  
K. P. M. Heirwegh ◽  
F Compernolle
Keyword(s):  
Biological Fluids ◽  
Subsequent Formation ◽  
Unequivocal Identification ◽  
Azo Derivatives ◽  
Biliverdin Ix ◽  
Trimethylsilyl Derivatives ◽  
The Individual ◽  
Layer Chromatography ◽  
Easy Differentiation

Procedures for the synthesis, separation and determination of structure of the bilirubin-IX isomers are described. 1. The four biliverdin-IX isomers were prepared by oxidative cleavage of haemin and were separated as their dimethyl esters. The individual esters were reduced with NaBH4, and the bilirubin esters obtained were subjected to alkaline hydrolysis yielding the corresponding bilirubin-IX isomers. 2. The bilirubin-IX isomers were structurally characterized (a) at the tetrapyrrolic stage by mass spectrometry of their trimethylsilyl derivatives and (b) by formation and structural analysis of their dipyrrolic ethyl anthranilate azo derivatives. 3. The absorption spectrum of bilirubin-IX α differed strikingly from the spectra of the other isomers. The presence of a pronounced shoulder around 453 nm in the spectrum of bilirubin-IXβ allows easy differentiation from bilirubin-IXdelta. Methylation of the carboxyl groups largely eliminates the spectral differences between the IXα- and non-α isomers. 4. The bilirubin-IX isomers are conveniently separated by t.l.c. Detection and unequivocal identification is possible on a micro-scale by (a) t.l.c. with respect to reference compounds and (b) subsequent formation and t.l.c. of the more stable ethyl anthranilate azopigments. 5. Pronounced differences in polarity, i.e. solvent distribution, between the bilirubin-IX isomers indicate that a re-evaluation of conclusions reached previously with regard to the presence in, or absence from, biological fluids of some isomers and their relative amounts is needed.

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