Synthesis of the four meso- oxyprotoporphyrin isomers

Jackson, Anthony H.; Rao, K.R.S. Sambasiva; Wilkins, M

doi:10.1039/c39820000794

Cited by 4 publications

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“…Protohaemin IX chloride was purchased from Sigma Chemical Co. Four benzoyloxyprotohaemin isomers were synthesized according to the method described by Sano et al [4,9]. For purification, alumina 90 and silica gel 60 precoated plates from Merck (Darmstadt, Germany), silica gel C-300 for chromatography from Wako and an h.p.l.c.…”

Section: Materials and Methods Materialsmentioning

confidence: 99%

“…Haem catabolism is an important biological process, which is catalysed by haem oxygenase (EC 1.14.99.3) and coupled NADPH-cytochrome c reductase (EC 1.6.2.4). The enzymic reaction has been studied in several laboratories during the past 20 years, and its main reaction pathway has been elucidated [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The first step is assumed to be hydroxylation at the porphyrin meso position to form an a-oxy derivative [5], which is further converted into biliverdin IXa via verdohaem IXa by two molecules of 02.…”

Section: Introductionmentioning

confidence: 99%

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

Yoshinaga

Sudo

Sano

1990

Biochemical Journal

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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.

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Section: Materials and Methods Materialsmentioning

confidence: 99%