Hematin compounds and bile pigments; their constitution, metabolism, and function, by R. Lemberg and J.W. Legge.

Legge, J. W.; Lemberg, R.

doi:10.5962/bhl.title.6453

Cited by 79 publications

(99 citation statements)

References 507 publications

(696 reference statements)

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“…5A). Breakdown of the complex is accompanied by disappearance of absorption in the Soret region, presumably as a result of auto-oxidative decomposition of the prosthetic group of peroxidase [29]. The presence of the amino acid (cysteic acid) prevents the disappearance of absorption in the Soret band, and the absorption maximum a t 458 mp shifts to 432 mp (Fig.5B).…”

Section: J M Zgliczy~yki T S T E L M a S Z Y~~s I~:~mentioning

confidence: 99%

Myeloperoxidase of Human Leukaemic Leucocytes

Zgliczyński¹,

Stelmaszyńska²,

Ostrowski³

et al. 1968

European Journal of Biochemistry

163

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Myeloperoxidase was isolated from leucocytes obtained from the blood of patients suffering from chronic granulocytic leukaemia. The enzyme was purified 850 fold and was homogeneous in ultracentrifuge and free boundary electrophoresis. The molecular weight of the enzyme was found to be about 160,000. The enzyme forms a spectrally characteristic complex with hydrogen peroxide with absorption maximum at 458 mμ. The spectrum of the native enzyme has absorption maxima at 430 and 570 mμ. The reduced enzyme is characterized by a spectrum with absorption maxima at 472 and 637 mμ. The investigated myeloperoxidase catalysed oxidation of amino acids by hydrogen peroxide. Products of the oxidation of amino acids were ammonia, carbon dioxide, and an aldehyde corresponding to the oxidized amino acid. The observed reaction of deamination and decarboxylation is activated by chloride ions. In the presence of the chloride ions the optimum of the reaction is shifted toward the higher pH values. The velocity of the reaction was found to be dependent on the concentration of the amino acid studied. Km values for various amino acids increased in the range 3.4 × 10−4 to 10−3 M in proportion to rising hydrophobic properties of the substrates. Taurine was found to be a competitive inhibitor in the examined reaction, and Ki values were in the range of 2 to 3 × 10−4 M, for different amino acids.

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Section: J M Zgliczy~yki T S T E L M a S Z Y~~s I~:~mentioning

confidence: 99%

Myeloperoxidase of Human Leukaemic Leucocytes

Zgliczyński¹,

Stelmaszyńska²,

Ostrowski³

et al. 1968

European Journal of Biochemistry

163

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“…Small amounts of other iron-containing compounds in erythrocytes have also been reported by Huennekens, Caffrey, Basford and Gabrio (1957) who isolated a haemoprotein presumed to he functional in the methaemoglobin reductase system; by Morrison (1961) who demonstrated another haemoprotein which may play some part in electron transport; and by Lemberg and Legge (1949) who isolated small amounts of choleglobin. The total amounts of these substances do not account for more than a small fraction of the total erythrocyte iron and they are not important in the fractions separated in the present work.…”

Section: Discussionmentioning

confidence: 80%

Separation of Haemoglobin Fractions in Rat Erythrocytes by Chemical and Physical Methods

Clark

1962

Aust J Exp Biol Med

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SUMMARY 59Fe which entered reticulocytes in vitro or was incorporated into developing red cells in vivo could be separated into fractions by a chemical procedure or by centrifugation of red cell haemolysates. The chemical separation depended on the solubility of the iron compounds in acid and in alkaline solutions and usually the ratio of the amounts of iron in the acid and alkaline extracts was 30 to 70. The addition of 10−3 M KCN to reticulocytes before addition of 59Fe changed this ratio to 85 to 15. Particulate matter separated from red cell haemolysates by centrifugation at 6,000 g. for 15 minutes also contained 59Fe. When the 59Fe was incorporated in vitro 28 p.c. was found in the stromal fraction and when 10−3 M KCN was used 90 p.c. was found in the stromal fraction. With in vivo incorporation the stromal fraction contained 19 p.c. of the 59Fe. The proportions of 59Fe extracted with acid or associated with the stroma were not related to the age of the reticulocytes and did not move to the other fractions on further incubation with iron. There is some evidence to suggest that the iron in the acid extract was that present in the stromal fraction but this has not been proved. However, the iron in all fractions must be principally haemoglobin iron obtained from functional haemoglobin. The separations achieved by the chemical and physical methods suggest that there are different forms of haemoglobin present in red cells which are capable of transporting oxygen.

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“…On the basis of earlier studies (7,32) hematin injected intravenously is still available for perfusion from the plasma up to 30 hr. This slow extraction is probably related to binding by hemopexin (33) or albumin (34). With certain reasonable assumptions based on the theoretical value for plasma volume and an exponential removal of 200 mg of injected hematin over 30 hr, a plasma concentration of 130 AM at the end of the infusion has been calculated.…”

Section: Discussionmentioning

confidence: 99%

Repression by Hematin of Porphyrin Biosynthesis in Erythrocyte Precursors in Congenital Erythropoietic Porphyria

Watson

Bossenmaier

Cardinal

et al. 1974

Proc. Natl. Acad. Sci. U.S.A.

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Hematin administered intravenously in a patient with congenital erythropoietic porphyria evidently entered erythrocyte precursors in the bone marrow, producing the well-known negative feedback repression of porphyrin biosynthesis with marked decline of porphyrin concentrations in urine, circulating plasma, and erythrocytes. A delay in the major segment of this effect corresponded roughly with the sum of the average transit times through the maturation compartments of the erythrocyte precursors. This delay was considerably longer than previously observed in the decline of porphyrin precursors after administration of hematin in patients with hepatic porphyria. The effect of hematin was compared with that of packed erythrocyte transfusions given at regular intervals in the same patient over a period of 2.5 years. In general, administration of hematin results in a reduction of porphyrin formation of the same order of magnitude, but of shorter duration, possibly in relation to the relatively small amounts of hematin infused.

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Hematin compounds and bile pigments; their constitution, metabolism, and function, by R. Lemberg and J.W. Legge.

Cited by 79 publications

References 507 publications

Myeloperoxidase of Human Leukaemic Leucocytes

Myeloperoxidase of Human Leukaemic Leucocytes

Separation of Haemoglobin Fractions in Rat Erythrocytes by Chemical and Physical Methods

Repression by Hematin of Porphyrin Biosynthesis in Erythrocyte Precursors in Congenital Erythropoietic Porphyria

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