Showing papers on "Protoporphyrin IX published in 1972"
47 citations
TL;DR: AlA synthetase activity was inhibited by sulfhydryl reagents such as PCMB, HgCl2 and NEM and by some metal ions such as Cu2+, Zn2+, Fe2+ and Fe3+ ions and almost all of these inhibitions were partially reversed by further incubation of the treated enzyme with 2–5 m m 2-mercaptoethanol at room temperature.
40 citations
TL;DR: The absorption spectrum of protoporphyrin IX in tetrahydrofuran solution has maxima at 404 (Soret band), 503, 536, 576 and 633 nm, and when added biacetyl was irradiated at its 436 nm absorption the bi acetyl phosphorescence was completely quenched.
Abstract: THE absorption spectrum of protoporphyrin IX in tetrahydrofuran solution has maxima at 404 (Soret band), 503, 536, 576 and 633 nm. Excitation at any of these wavelengths produced an intense red emission with its maximum at 635 nm1. The same emission spectrum was observed when added biacetyl was irradiated at its 436 nm absorption. In these conditions the biacetyl phosphorescence was completely quenched. Additionally, molecular oxygen quenched the protoporphyrin IX emission spectrum following Stern-Volmer kinetics. Typical experimental results, obtained at 25° C, are plotted in Fig. 1.
35 citations
TL;DR: The final steps in heme synthesis take place within mitochondria while the acceptor apoproteins are synthesized on the endoplasmic reticulum, and heme export from mitochondria is dependent on protein in the suspending medium.
Abstract: The final steps in heme synthesis take place within mitochondria while the acceptor apoproteins are synthesized on the endoplasmic reticulum. When 14C-δ-aminolevulinic acid is used as a heme precursor in intact rats, measurable 14C-heme is found to be associated with the microsomes within 10 min of intraperitoneal injection. This rapid transfer of heme from mitochondria was studied in vitro using isolated rat liver mitochondria, and protoporphyrin IX and 59Fe as heme precursors. These mitochondria synthesize heme when suspended in whole cell sap and this is only partially reduced by substituting Sephadex G-25 filtered cell sap or sucrose. Mitochondria incubated in G-25 filtered cell sap or sucrose synthesize equivalent amounts of heme but those in sucrose export little heme into the surrounding medium. Heme export from mitochondria is dependent on protein in the suspending medium. In cell sap, heme is associated with multiple proteins and no single carrier was identified. Heme probably makes its way from ...
29 citations
TL;DR: The conversion of coproporphyr inogen III to protoporphyrin IX was demonstrated in the enzyme obtained from an obligate anaerobe, Chromatium D, only when the assay was conducted aerobically, and alternative electron acceptors could not replace molecular O2.
22 citations
TL;DR: In this article, an α,α-dicarboxydipyrrylmethane is decarboxylated in N,N-dimethylformamide and the product converted into its monoimmonium salt (Vilsmeier-Haack intermediate) with benzoyl chloride, affords a bilene-b which with copper acetate-pyridine gives a normal porphyrin.
Abstract: α-Formyl-α'-methyldipyrrylmethanes have been shown to react with α,α'- dicarboxydipyrrylmethanes to give hexapyrrenes which cyclize with copper acetate in pyridine to yield meso-pyrrolylporphyrins. However, if an α,α'-dicarboxydipyrrylmethane is decarboxylated in N,N-dimethylformamide and the product converted into its monoimmonium salt (Vilsmeier-Haack intermediate) with benzoyl chloride this salt with an α-formyl-α'-methyldipyrrylrnethane affords a bilene-b which with copper acetate-pyridine gives a normal porphyrin. This latter procedure has been adapted to prepare tetrapyrroles of the protoporphyrin IX type. A synthesis of pemptoporphyrin dimethyl ester is reported.
20 citations
TL;DR: In this paper, Coproporphyrinogen-III (1) was shown to be converted biochemically into protoporphrin-IX with loss of one hydrogen atom from each propionate residue on rings A and B and the 3H-tracer results are consistent with a stereospecific process.
Abstract: Coproporphyrinogen-III (1) is shown to be converted biochemically into protoporphyrin-IX (4) with loss of one hydrogen atom from each propionate residue on rings A and B and the 3H-tracer results are consistent with a stereospecific process.
19 citations
TL;DR: It is suggested that the mechanism of the photoprotective action against 320-450nm radiation has many features similar to that of radioprotection by thiols and glycerol against ionizing radiation.
15 citations
TL;DR: In this paper, the 13C-n.m.r. spectra of porphyrin-IX and other porphrinogen are used to assign assignments to porphinogen signals.
Abstract: [11-13C]Porphobilinogen is synthesised from [13C]methanol and is converted biochemically into [meso-13C]protoporphyrin-IX; assignments are made of signals in the 13C-n.m.r. spectra of protoporphyrin-IX and of other porphyrins.
11 citations
TL;DR: A temperature-sensitive respiration-deficient mutant of yeast lacks hemoproteins and accumulates coproporphyrin III when cultivated at elevated temperatures and changes in the number and structure of mitochondria were associated with changes in respiratory activity.
Abstract: A temperature-sensitive respiration-deficient mutant of yeast lacks hemoproteins and accumulates coproporphyrin III when cultivated at elevated temperatures. Cells grown at 20 C respired normally and contained cytochromes a, b, and c. Cells grown at 35 C showed respiration-deficient mutant characters; they did not respire, lacked cytochromes, and accumulated coproporphyrin III. Addition of protoporphyrin IX or protohemin IX to the culture medium restored the respiratory activity of this mutant during growth at 35 C. The activities of various enzymes, including succinate-2,6-dichlorophenol indophenol (DCPIP), reduced nicotinamide adenine dinucleotide (NADH(2))-DCPIP, succinate-cytochrome c, and NADH(2)-cytochrome c oxidoreductase, and cytochrome oxidase, and the cytochrome c content of cells cultured in various conditions were determined. Changes in the number and structure of mitochondria were associated with changes in respiratory activity.
8 citations
TL;DR: In this paper, the side-chains of the readily available protoporphyrin-IX dimethyl ester were manipulated to obtain coproporphrin-III tetramethyl esters in an overall yield of 37%.
Abstract: Manipulation of the vinyl side-chains of the readily available protoporphyrin-IX dimethyl ester (2) allows the synthesis of coproporphyrin-III tetramethyl ester (1) in an overall yield of 37%.
TL;DR: Biochemical scrambling of the type-III porphyrinogen system is eliminated by showing that specifically labelled coproporphyr inogen-III is enzymically converted into protoporphyrIn-IX labelled at the corresponding sites.
Abstract: Biochemical scrambling of the type-III porphyrinogen system is eliminated by showing that specifically labelled coproporphyrinogen-III (2) is enzymically converted into protoporphyrin-IX (5a) labelled at the corresponding sites.