Showing papers on "Protoporphyrin IX published in 1980"
TL;DR: Hemopexin is able to compete effectively with albumin for coproporphyrin I or III only at low molar ratios of the two proteins and seems unlikely to bind a significant portion of these porphyrins at the molar ratio of hemopexIn and albumin found in human serum.
89 citations
TL;DR: In this article, the triplet formation of protoporphyrin IX as the dication, monocation and free base in several solvent systems is rationalised in terms of the species existing as a monomer in organic or detergent solvents and as an aggregated species in aqueous environments.
Abstract: Laser and conventional flash photolysis have been used to obtain the triplet—triplet absorption spectra, triplet lifetimes, rates of oxygen quenching and quantum efficiencies of triplet formation of protoporphyrin IX as the dication, monocation and free base in several solvent systems The results are rationalised in terms of protoporphyrin IX existing as a monomer in organic or detergent solvents and as an aggregated species in aqueous environments
38 citations
Journal Article•
TL;DR: The results establish that N-alkylation of prosthetic heme during attempted metabolism of olefinic bonds is the cause of cytochrome P-450 destruction and suggest that N-(2-hydroxyethyl)protoporphyrin IX (dimethyl ester) is the probable structure of the ethylene adduct.
Abstract: Destruction of phenobarbital-inducible cytochrome P-450 during metabolism of 4-ethyl-1-hexene and ethylene results in accumulation of abnormal hepatic porphyrins. Field desorption mass spectrometric analysis of these "green" porphyrins has shown that they are 1:1:1 stoichiometric adducts of protoporphyrin IX (isolated as the dimethyl ester), the olefin in question, and an oxygen atom. The electronic absorption spectra of the adducts, as both free bases and zinc complexes, are virtually superimposable with the corresponding spectra of the dimethyl ester (DME) of synthetic N-methylprotoporphyrin IX. The zinc complexes of both N-methylprotoporphyrin IX (DME) and the 4-ethyl-1-hexene adduct exhibit mass spectrometric molecular ions attributable to the porphyrin plus zinc plus a chloride ion, although evidence for thermal generation of protoporphyrin IX (DME) from both of these porphyrins in the mass spectrometer is provided. These results establish that N-alkylation of prosthetic heme during attempted metabolism of olefinic bonds is the cause of cytochrome P-450 destruction. They also suggest that N-(2-hydroxyethyl)protoporphyrin IX (dimethyl ester) is the probable structure of the ethylene adduct.
35 citations
TL;DR: Analytical recovery ranged from 84 to 92%, day-to-day precision (CV) from 5 to 12%.
Abstract: We describe a method for simultaneously measuring concentrations of coproporphyrin, zinc protoporphyrin IX, and protoporphyrin IX in whole blood by liquid chromatography, with use of reversed-phase ion-pair system, fluorometric detection, and internal standardization. Each analysis requires 10 microL of whole blood and 15 min total analysis time. Analytical recovery ranged from 84 to 92%, day-to-day precision (CV) from 5 to 12%. Uroporphyrin, though not studied in detail, can also be detected by this method.
29 citations
TL;DR: The results support the suggestion by Elder & Evans that the prophyrin to be taken up by the inner mitochondrial membrane belongs to the protoporphyrin(ogen) IX series.
Abstract: Rat liver mitochondria accumulate protoporphyrin IX from the suspending medium into the inner membrane in parallel with the magnitude of the transmembrane K+ gradient (K+in/K+out). Only protoporphyrin IX taken up in parallel with the transmembrane K+ gradient is available for haem synthesis. Coproporphyrins (isomers I and III) are not taken up by the mitochondria. The results support the suggestion by Elder & Evans [(1978) Biochem. J. 172, 345-347] that the prophyrin to be taken up by the inner mitochondrial membrane belongs to the protoporphyrin(ogen) IX series. Protoporphyrin IX at concentrations above 15 nmol/mg of protein has detrimental effects on the structural and functional integrity of the mitochondria. The relevance of these effects to the hepatic lesion in erythropoietic protoporphyria is discussed.
27 citations
TL;DR: Results indicate that the formation of an inhibitor after the administration of DDC is due to the catabolism of hepatic heme to a substance with porphyrin-like properties and with profound inhibitory characteristics toward ferrochelatase activity.
18 citations
TL;DR: The concept that cobalt protoporphyrin IX is rapidly produced in vivo after the administration of cobaltous chloride and may be responsible for the observed inhibition of hepatic heme biosynthesis is supported.
17 citations
TL;DR: It is proposed that the iron-porphyrin moiety of digested hemoglobin is a common binding site for the accumulation of the schizontocidal drugs in the autophagosomes of the malarial parasite.
16 citations
TL;DR: In this paper, the formation of the magnesium chelate of protoporphyrin IX with traces of its monomethyl ester was obtained on incubation of crude plastid preparations from greening cucumber cotyledons with L-glutamate.
16 citations
TL;DR: Results indicate that electronic changes in the center of the porphyrin ring can be detected by quantitative immunochemical procedures as structural changes on the surface of the hemoglobin molecule.
8 citations
TL;DR: The effect of the central Mg atom in the protoporphyrin IX ring was also considerable as discussed by the authors, which is manifested in the hypochromic effect in absorption spectra.
Abstract: Vinyl copolymers with pendant porphyrin dimers were synthesized first by the dimerizations of chlorophyll-α and protoporphyrin IX via the ethylenebisamide linkage, then by copolymerization of the vinylbenzyl esters of the resulting dimers with N-vinylpyrrolidone or the esterification reaction of the dimers with chloromethylstyrene copolymers. Dimer-pendant copolymers with vinyl pyrrolidone catalyzed photoredox systems in aqueous solutions more efficiently than the corresponding monomer analogs, presumably because of the interactions exerted between the two combined porphyrin rings, which are manifested in the hypochromic effect in absorption spectra. The effect of the central Mg atom in the protoporphyrin IX ring was also considerable.