scholarly journals Cytosol intermediates in the transport of iron

Blood ◽  
1980 ◽  
Vol 55 (6) ◽  
pp. 1051-1055 ◽  
Author(s):  
MT Nunez ◽  
ES Cole ◽  
J Glass
Keyword(s):  
Molecular Weight ◽  
Plasma Membrane ◽  
Binding Protein ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Iron Binding ◽  
The Third ◽  
Initial Values ◽  
Iron Supply ◽  
Iron Binding Protein

Three 59Fe-labeled nonheme components of the cytosol were identified when rabbit reticuloyctes were incubated with 59Fe-labeled plasma under conditions in which the iron supply was not limiting. Two of these components were identified as ferritin and transferrin. The latter was characterized by gel filtration as having apparent molecular weight higher than transferrin, indicating that the transferrin may be complexed to another moiety. The third component, referred to as iron- binding protein-I (IBP-I), is as yet uncharacterized. When the reticulocytes were incubated with unlabeled plasma after pulse-labeling with 59Fe-labeled plasma, 59Fe radioactivity in these cytosol components decreased; after 15 min of chase, the 59Fe in ferritin, transferrin, and IBP-I fell to 64.6%, 26.5%, and 65.8% of the initial values, respectively. A good correlation existed between the decrease of 59Fe in these three nonheme compartments and the associated increase in 59Fe-heme. The data presented suggest that cytosol ferritin, transferrin, and IBP-I are intermediates in the transport of 59Fe from the plasma membrane to the mitochondria.

scholarly journals Cytosol intermediates in the transport of iron

Blood ◽  
1980 ◽  
Vol 55 (6) ◽  
pp. 1051-1055 ◽  
Author(s):  
MT Nunez ◽  
ES Cole ◽  
J Glass
Keyword(s):  
Molecular Weight ◽  
Plasma Membrane ◽  
Binding Protein ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Iron Binding ◽  
The Third ◽  
Initial Values ◽  
Iron Supply ◽  
Iron Binding Protein

Abstract Three 59Fe-labeled nonheme components of the cytosol were identified when rabbit reticuloyctes were incubated with 59Fe-labeled plasma under conditions in which the iron supply was not limiting. Two of these components were identified as ferritin and transferrin. The latter was characterized by gel filtration as having apparent molecular weight higher than transferrin, indicating that the transferrin may be complexed to another moiety. The third component, referred to as iron- binding protein-I (IBP-I), is as yet uncharacterized. When the reticulocytes were incubated with unlabeled plasma after pulse-labeling with 59Fe-labeled plasma, 59Fe radioactivity in these cytosol components decreased; after 15 min of chase, the 59Fe in ferritin, transferrin, and IBP-I fell to 64.6%, 26.5%, and 65.8% of the initial values, respectively. A good correlation existed between the decrease of 59Fe in these three nonheme compartments and the associated increase in 59Fe-heme. The data presented suggest that cytosol ferritin, transferrin, and IBP-I are intermediates in the transport of 59Fe from the plasma membrane to the mitochondria.

scholarly journals The superoxide-dependent transfer of iron from ferritin to transferrin and lactoferrin

1988 ◽  
Vol 256 (3) ◽  
pp. 923-928 ◽  
Author(s):  
H P Monteiro ◽  
C C Winterbourn
Keyword(s):  
Lipid Peroxidation ◽  
Free Radicals ◽  
Xanthine Oxidase ◽  
Binding Protein ◽  
Gel Filtration ◽  
Iron Binding ◽  
Oxidase System ◽  
Oxidative Reactions ◽  
Phospholipid Liposomes ◽  
Iron Binding Protein

By the use of gel filtration and [59Fe]ferritin, apotransferrin and apolactoferrin were shown to take up iron released from ferritin by superoxide generated by hypoxanthine and xanthine oxidase. Apotransferrin also inhibited uptake of released iron by ferrozine. Ferritin and the xanthine oxidase system induced lipid peroxidation in phospholipid liposomes. This peroxidation was inhibited by apotransferrin or apolactoferrin. Thus, although superoxide and other free radicals can release iron from ferritin, either iron-binding protein, if present, should take up this iron and prevent its catalysing subsequent oxidative reactions.

scholarly journals Studies on the appearance of a hepatic copper-binding protein in normal and zinc-deficient rats

1976 ◽  
Vol 36 (1) ◽  
pp. 101-112 ◽  
Author(s):  
I. Bremner ◽  
N. T. Davies
Keyword(s):  
Molecular Weight ◽  
Metal Binding ◽  
Binding Protein ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Low Molecular Weight ◽  
Copper Binding ◽  
Hepatic Copper ◽  
Copper Binding Protein ◽  
Molecular Weight Form

1. A study has been made by gel-filtration techniques of the soluble copper- and zinc-binding proteins in rat liver after both intraperitoneal injection of Cu and dietary Cu supplementation.2. Liver Cu and Zn concentrations increased after injection of Cu, both metals accumulating in the cytosol, mainly in a fraction with an apparent molecular weight of (about 12 000)3. When Zn-deficient rats were injected with Cu, there was little change in liver Zn concentration and the occurrence of Cu in the low-molecular-weight form (about 12 000) was more transient. At most periods after injection, Cu accumulated mainly in a fraction with a molecular weight greater than 65 000.4. When the rats were Cu-loaded by dietary supplementation, virtually no Cu or Zn was found in the low-molecular-weight form in Zn-deficient rats, although they were found in the Zn-supplemented animals.5. The results suggest that Zn is essential for the accumulation of Cu in this form, but not for Cu to stimulate production of the metal-binding protein by a process requiring active protein synthesis.

Heat Shock Protein 90 Recognized as an Iron-Binding Protein Associated with the Plasma Membrane of HeLa Cells

2004 ◽  
Vol 14 (1-2) ◽  
pp. 41-46 ◽  
Author(s):  
Jan Kovár ◽  
Hana Stýbrová ◽  
Petr Novák ◽  
Marie Ehrlichová ◽  
Jaroslav Truksa ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Hela Cells ◽  
Binding Protein ◽  
Heat Shock Protein 90 ◽  
Iron Binding ◽  
Iron Binding Protein

EVIDENCE FOR A PLASMINOGEN ACTIVATOR INHIBITOR BINDING PROTEIN IN PLASMA

1987 ◽  
Author(s):  
B Wiman ◽  
T Carlsson ◽  
J Chmielewska
Keyword(s):  
Molecular Weight ◽  
Human Plasma ◽  
Plasminogen Activator ◽  
Binding Protein ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Plasminogen Activator Inhibitor ◽  
Guanidinium Chloride ◽  
Pathophysiological Role ◽  
Activator Inhibitor

For several years it has been known that plasminogen activator inhibitor in plasma behaves as a high molecular weight compound on gelfiltration, in spite of that the molecular weight is only 50,000 in the presence of sodium dodecylsul-phate. The reason for this has so far been unknown. On gelfiltration of plasma, to which purified latent PAI from HT 1080 cells was added, the PAI antigen gel-filtered as a 50,000 Mr protein. However, if the latent form of PAI was reactivated by guanidinium chloride prior to the gel-filtra-tion experiment, an apparent molecular weight of about 250.000 for PAI antigen and activity was observed. If more than 10,000 U of PAI activity was added/mL of normal human plasma, excess PAI occurred at 50,000 Mr on gel-filtration. Human normalplasma was subjected to gel-filtration on sepha-cryl S-300 or Sepharose 6B and the fractions were checked for capacity to transform low Mr functional PAI to high Mr functional PAI. This capacity was only found in the 150 - 200,000 Mr region of the chromatogram. These data suggest that human plasma contains a protein that binds active forms of PAI. The complex of this protein and PAI could be dissociated by gelfiltration in the presence of 3 mol/L guanidinium chloride or 0.1 % (w/v) sodium dodecylsulphate. The physiological or pathophysiological role of the PAI-binding protein is not known. Work with purification of the protein is in progress. Considerable purification have so far been obtained by precipitation with polyethylenglycol 6000 (0-6%), gel-filtration on Sephacry1 S-300, followed by affinity chromatography on heparin-Sepharose.

scholarly journals Isolation, purification and characterization of an iron-binding protein from the horseshoe crab (Limulus polyphemus)

1988 ◽  
Vol 252 (1) ◽  
pp. 151-157 ◽  
Author(s):  
R Topham ◽  
B Cooper ◽  
S Tesh ◽  
G Godette ◽  
C Bonaventura ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Horseshoe Crab ◽  
Binding Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Limulus Polyphemus ◽  
Evolutionary Development ◽  
Iron Binding ◽  
Oxygen Carriers ◽  
Iron Binding Protein

The presence of an iron-binding protein in the haemolymph of the horseshoe crab, Limulus polyphemus, was detected by gel filtration of 59Fe-labelled haemolymph. Lysis of amoebocytes did not change the amount of iron-binding protein in haemolymph samples. The protein was purified to homogeneity by ion-exchange chromatography. The molecular mass of the purified protein was estimated to be 282,000 +/- 10,000 Da by gel filtration and analytical ultracentrifugation. SDS/polyacrylamide-gel electrophoresis demonstrated that the protein is composed of ten subunits having a molecular mass of 28,000 +/- 2,000 Da. The purified, unlabelled protein efficiently sequestered 59Fe in the absence of haemolymph indicating that no other haemolymph factors are required for the incorporation of iron into the protein. No 59Fe was removed from the purified protein with EDTA or 2,2′-bipyridyl. Partial removal of 59Fe was achieved by dialysis with nitrilotriacetic acid or desferal. Analysis of the iron-loaded protein indicated that each subunit has the capacity to bind two iron atoms with high affinity. The isolation of an iron-binding protein from L. polyphemus supports the proposal that such proteins are an ancient evolutionary development not necessarily linked to the appearance of iron proteins which serve as oxygen carriers.

Physico-Chemical Properties of Recombinant Desulphatohirudin

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Alpha Helix ◽  
Apparent Molecular Weight ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Recombinant Hirudin ◽  
Physico Chemical ◽  
Recombinant Molecule

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)

Zinc- and copper-binding proteins in the plasma of winter flounder (Pseudopleuronectes americanus)

1980 ◽  
Vol 58 (4) ◽  
pp. 609-613 ◽  
Author(s):  
P. E. Fletcher ◽  
G. L. Fletcher
Keyword(s):  
Molecular Weight ◽  
Binding Proteins ◽  
Binding Protein ◽  
Gel Filtration ◽  
Protein S ◽  
Egg Yolk ◽  
Winter Flounder ◽  
Zinc Binding ◽  
Copper Binding ◽  
Copper Binding Proteins

Zinc- and copper-binding proteins were isolated from the plasma of winter flounder using gel filtration chromatography. A single copper-binding protein fraction of molecular weight 170 000 was isolated from the plasma of both sexes.In male and female flounder over 95% of the plasma zinc was associated with a zinc-binding protein(s) with a molecular weight of 76 000. In male flounder the remaining zinc appeared to be bound to a protein(s) of molecular weight 186 000. In female flounder the remaining 5% of the zinc was associated with two zinc-binding fractions with apparent molecular weights of 186 000 and 340 000 – 370 000.Extracts of plasma vitellogenin and egg yolk proteins revealed significant quantities of zinc and copper. It is hypothesized that the female specific zinc-binding protein (340 000 – 370 000) was vitellogenin.

Sign in / Sign up

Export Citation Format

Share Document