Structural basis for cooperative oxygen binding and bracelet-assisted assembly of Lumbricus terrestris hemoglobin
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چکیده
منابع مشابه
Structural basis for cooperative oxygen binding and bracelet-assisted assembly of Lumbricus terrestris hemoglobin
The iron-containing hemoglobins (Hbs) are essential proteins to serve as oxygen transporters in the blood. Among various kinds of Hbs, the earthworm Hbs are the champions in carrying oxygen due to not only their large size but also the unusually high cooperativity of ligand binding. However, the cooperative oxygen binding mechanisms are still mostly unknown. Here we report the cryo-electron mic...
متن کاملBracelet protein: a quaternary structure proposed for the giant extracellular hemoglobin of Lumbricus terrestris.
The complete dissociation of the hexagonal bilayer structure of Lumbricus terrestris hemoglobin (3900 kDa) at neutral pH, in the presence of urea, guanidine hydrochloride, sodium perchlorate, potassium thiocyanate, sodium phosphotungstate, and sodium phosphomolybdate, followed by gel filtration at neutral pH on Sephacryl S-200 or Superose 6, produced two fragments, II (65 kDa) and III (17 kDa);...
متن کاملModels for Cooperative Oxygen Binding in Hemoglobin
Equilibrium measurements of oxygen binding by 0 iron(II) and cobalt(II) picket fence porphyrins exhibit p^2, ΔΗ°, and AS° values close to those of myoglobin and cobalt myoglobin respectively. In contrast the CO affinities of simple iron(II) porphyrins are much greater than those of the hemoproteins, hemoglobin (Hb) and myoglobin (Mb). This difference is apparently caused by distal residues in H...
متن کاملStoichiometry of subunits and heme content of hemoglobin from the earthworm Lumbricus terrestris.
The extracellular hemoglobin (Hb) of the earthworm, Lumbricus terrestris, has four major O2-binding chains, a, b, c (forming a disulfide-linked trimer), and d ("monomer"). Additional structural chains, "linkers," are required for the assembly of the approximately 200-polypeptide molecule. The proportion of linker chains had been reported to be one-third of the total mass on the basis of densito...
متن کاملThe structure of the gene encoding chain c of the hemoglobin of the earthworm, Lumbricus terrestris.
The complete nucleotide sequence of the gene for chain c of hemoglobin of the earthworm Lumbricus terrestris has been determined. The sequence of 4037 base pairs (bp) includes about 310 bp of 5'-flanking sequence and 110 bp 3' to the poly(A) site. Comparison of cDNA and genomic sequences shows four silent differences in codons that suggest the presence of at least two genes. The coding sequence...
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ژورنال
عنوان ژورنال: Scientific Reports
سال: 2015
ISSN: 2045-2322
DOI: 10.1038/srep09494