The reactivity of CysF9[93]β sulphydryl group of des-HisHC3[146]β human haemoglobin A

2011 ◽  
Vol 10 (67) ◽  
Author(s):  
Babalola
Keyword(s):  
Human Haemoglobin ◽  
Sulphydryl Group

Location of the reactive sulphydryl group in human globin

1973 ◽  
Vol 38 (2) ◽  
pp. 465-467
Author(s):  
J. Sojka ◽  
Z. Hrkal ◽  
Z. Vodrážka
Keyword(s):  
Sulphydryl Group

Comparison of human haemoglobin and globin in denaturation

1976 ◽  
Vol 41 (6) ◽  
pp. 1811-1819
Author(s):  
M. Kodíček ◽  
Z. Vodrážka
Keyword(s):  
Human Haemoglobin

scholarly journals Crystallization and X-ray diffraction data analysis of human deoxyhaemoglobin A0 fully stripped of any anions

1999 ◽  
Vol 55 (11) ◽  
pp. 1914-1916 ◽  
Author(s):  
F. A. V. Seixas ◽  
W. F. de Azevedo ◽  
M. F. Colombo
Keyword(s):  
Diffraction Data ◽  
Oxygen Affinity ◽  
X Ray Diffraction ◽  
Structural Explanation ◽  
Human Haemoglobin ◽  
X Ray ◽  
High Resolution Structure ◽  
Allosteric Properties

In this work, initial crystallographic studies of human haemoglobin (Hb) crystallized in isoionic and oxygen-free PEG solution are presented. Under these conditions, functional measurements of the O2-linked binding of water molecules and release of protons have evidenced that Hb assumes an unforeseen new allosteric conformation. The determination of the high-resolution structure of the crystal of human deoxy-Hb fully stripped of anions may provide a structural explanation for the role of anions in the allosteric properties of Hb and, particularly, for the influence of chloride on the Bohr effect, the mechanism by which Hb oxygen affinity is regulated by pH. X-ray diffraction data were collected to 1.87 Å resolution using a synchrotron-radiation source. Crystals belong to the space group P21212 and preliminary analysis revealed the presence of one tetramer in the asymmetric unit. The structure is currently being refined using maximum-likelihood protocols.

Reductive Activation of Carbon Tetrachloride by Human Haemoglobin

1993 ◽  
Vol 21 (1) ◽  
pp. 57-64
Author(s):  
Roberta Ferrara ◽  
Michela Rezzadore ◽  
Stefano Cazzaro ◽  
Roberto Tolando ◽  
Maurizio Manno
Keyword(s):  
Carbon Monoxide ◽  
Carbon Tetrachloride ◽  
Anaerobic Incubation ◽  
Reductive Activation ◽  
Anaerobic Conditions ◽  
Prosthetic Group ◽  
Experimental Conditions ◽  
Human Haemoglobin ◽  
Reductive Metabolism

The reductive metabolism of carbon tetrachloride (CC14) by human haemoglobin (Hb) was observed in vitro by absolute absorption spectra recorded under anaerobic conditions. The following results were obtained: 1) a decrease of the 430nm peak typical of free reduced Hb (Hb2+); 2) the formation of a shoulder of absorbance, attributable to the production of a complex between Hb2+ and a metabolite of CC14 carbon monoxide (Hb-CO); and 3) the oxidation of some Hb2+ to methaemoglobin (Hb3+). The concentration of these three forms — Hb2+, Hb-CO and Hb3+ — during anaerobic incubation of Hb with CC14 was calculated algebraically from the absolute spectra. CO production was then calculated from the concentration of Hb-CO, using a suitable calibration curve. Interestingly, under identical experimental conditions, a substrate-dependent loss of Hb-derived haem, but not of Hb itself nor of haem-derived porphyrin fluorescence, was measured. Preliminary HPLC studies to clarify the discrepancy and, in particular, the role and fate of the haem group, showed two substrate-dependent modified haem products. The results indicate that human Hb is able to catalyse the reductive activation of CCl4, and suggest that, during the process, its prosthetic group haem may be modified by CC14 metabolites to products which maintain a tetrapyrrolic structure but are unable to react with pyridine.

Age-dependent changes in volume and haemoglobin content of erythrocytes in the carp (Cyprinus carpio L.)

1989 ◽  
Vol 141 (1) ◽  
pp. 133-149 ◽  
Author(s):  
W. Speckner ◽  
J. F. Schindler ◽  
C. Albers
Keyword(s):  
Gel Filtration ◽  
Linear Increase ◽  
Human Erythrocytes ◽  
Main Peak ◽  
Red Cell ◽  
Human Haemoglobin ◽  
Cell Fractions ◽  
Haemoglobin Content

Carp erythrocytes were fractionated by angle-head centrifugation which yielded fractions with a linear increase in density. Haematological examinations revealed that the heavier red blood cells of carp had greater volumes (MCV), more haemoglobin (MCH) and higher haemoglobin concentrations (MCHC) than light ones. The same experiments with human red cell fractions yielded a decrease in MCV, constant MCH and an increase in MCHC. Haemoglobin content in individual erythrocytes was also determined by scanning stage absorbance cytophotometry to establish the frequency distribution of the cellular haemoglobin contents. In carp, the distribution was symmetrical with the means increasing with density. No such change with cell density was found in human erythrocytes. Both carp and human erythrocytes incorporated [2-14C]glycine in vitro. After gel filtration, radioactivity was detected in carp, but not in human, haemoglobin fractions. 14C was found in all three haemoglobin fractions, obtained by isoelectric focusing, and was present in the haem and in the globin. [2-14C]glycine-labelled erythrocytes were reinjected into chronically cannulated carp and followed in vivo for several months. With time, the main peak of scintillation counts shifted from red cell fractions of low to high density. This is considered as evidence that density and age of red cells in carp are positively correlated and that erythrocytes can synthesize haemoglobin while circulating in the peripheral blood.

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