scholarly journals 1H-n.m.r. and c.d. studies of haem orientational disorder in sperm-whale myoglobin and human haemoglobin

1988 ◽  
Vol 250 (3) ◽  
pp. 853-858 ◽  
Author(s):  
H S Aojula ◽  
M T Wilson ◽  
G R Moore ◽  
D J Williamson
Keyword(s):  
Sperm Whale ◽  
Orientational Disorder ◽  
Human Haemoglobin ◽  
Minor Isomer ◽  
Alternative Method ◽  
Freeze Dried ◽  
Ph Jump ◽  
Sperm Whale Myoglobin ◽  
Soret Region

1H-n.m.r. and c.d. studies on sperm-whale myoglobin show that the c.d. signal in the Soret region is inversely and linearly related to the proportion of minor isomer present. An alternative method, ‘pH jump’, is described for inducing orientational disorder in sperm-whale myoglobin without recourse to reconstitution. 1H-n.m.r. studies on human haemoglobin A indicate little heterogeneity in freshly isolated haemoglobin A, but the effect is enhanced in freeze-dried Sigma haemoglobin A.

The structure of haemoglobin. IX. A three-dimensional Fourier synthesis at 5.5 Å resolution: description of the structure

1962 ◽  
Vol 265 (1321) ◽  
pp. 161-187 ◽  
Keyword(s):  
Tertiary Structure ◽  
Three Dimensional ◽  
Sperm Whale ◽  
Anomalous Scattering ◽  
Fourier Synthesis ◽  
Human Haemoglobin ◽  
Contour Maps ◽  
To Come ◽  
Polypeptide Chains ◽  
Sperm Whale Myoglobin

The electron density distribution in the unit cell is calculated at intervals of approximately 2Å and plotted in a series of sections parallel to (010). The contour maps show that haemoglobin consists of four subunits in a tetrahedral array. The subunits are identical in pairs in accordance with the twofold symmetry of the molecule. The two pairs are very similar in structure, and the members of each pair closely resemble the molecule of sperm-whale myoglobin. The four haem groups lie in separate pockets at the surface of the molecule. The positions of the iron atoms are confirmed by comparison of observed and calculated anomalous scattering effects, which also serve to determine the absolute configuration of the molecule. The four subunits found by X-ray analysis correspond to the four polypeptide chains into which haemoglobin can be divided by chemical methods. In horse haemoglobin the amino acid sequence within these chains is still partly unknown, but in human haemoglobin it has already been determined. Comparison of this sequence with the tertiary structure of the chains as now revealed in horse haemoglobin and with the atomic model of sperm-whale myoglobin recently obtained by Kendrew and his collaborators shows many interesting relations. Prolines appear to come where the chains turn corners or where their configuration is known to be non-helical. On the other hand, the chains also have corners which contain no proline. Certain residues appear to be structurally vital, because they appear in identical positions in myoglobin and in the two chains of haemoglobin, while in other parts of the molecule a wide variety of different side-chains appears to be allowed.

scholarly journals Functional consequences of haem orientational disorder in sperm-whale and yellow-fin-tuna myoglobins

1987 ◽  
Vol 243 (1) ◽  
pp. 205-210 ◽  
Author(s):  
H S Aojula ◽  
M T Wilson ◽  
I E G Morrison
Keyword(s):  
Ligand Binding ◽  
Kinetic Parameters ◽  
Sperm Whale ◽  
Binding Kinetics ◽  
Orientational Disorder ◽  
Binding Properties ◽  
Functional Consequences ◽  
Kinetics Of ◽  
Sperm Whale Myoglobin ◽  
O2 Dissociation

Ligand-binding kinetics of native and reconstituted sperm-whale myoglobin were studied in relation to haem orientational disorder by rapid kinetic methods. In addition, native yellow-fin-tuna myoglobin with significant amount of haem disorder was also used. The O2 dissociation and association rates were found for the proteins with different degrees of haem disorder, and these results suggest that the isomers are characterized by almost identical kinetic parameters. Rates of CO recombination after photolysis were also identical for the two orientational isomers. The results clearly indicate that the rotation of the haem about the alpha-gamma meso axis has little or no effect on the ligand-binding properties of these myoglobins.

Heme orientational disorder in reconstituted and native sperm whale myoglobin

1983 ◽  
Vol 168 (4) ◽  
pp. 887-896 ◽  
Author(s):  
Gerd N. La Mar ◽  
N.L. Davis ◽  
Daniel W. Parish ◽  
Kevin M. Smith
Keyword(s):  
Sperm Whale ◽  
Orientational Disorder ◽  
Sperm Whale Myoglobin

scholarly journals Prediction and conformation by synthesis of two antigenic sites in human haemoglobin by extrapolation from the known antigenic structure of sperm-whale myoglobin

1977 ◽  
Vol 167 (1) ◽  
pp. 275-278 ◽  
Author(s):  
A L Kazim ◽  
M Z Atassi
Keyword(s):  
Sperm Whale ◽  
Antigenic Structure ◽  
Homologous Proteins ◽  
Human Haemoglobin ◽  
Antigenic Sites ◽  
Inductive Effects ◽  
Structural Analogy ◽  
Starting Model ◽  
Sperm Whale Myoglobin

The complete antigenic structure of sperm-whale myoglobin was previously determined in our laboratory. By structural analogy with myoglobin, two regions in human haemoglobin were predicted to comprise antigenic sites. One region was on the alpha-chain [alpha-(15-23)] and the other on the beta-chain [beta-(16-23)]. These two regions were synthesized, purified and characterized, and their immunochemistry was studied. Each peptide was able specifically to bind considerable amounts of haemoglobin antibodies. In a set of homologous proteins, barring any drastic conformational or electrostatic inductive effects exerted by the substitutions, and allowing for obstruction due to subunit interaction, the determination of the antigenic structure of one protein may serve as a useful starting model for the others.

The amino acid sequence of human myoglobin and its minor fractions

1974 ◽  
Vol 186 (1084) ◽  
pp. 249-279 ◽  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Three Dimensional ◽  
Sperm Whale ◽  
Dimensional Structure ◽  
Human Haemoglobin ◽  
Human Myoglobin ◽  
Main Component ◽  
Haemoglobin Molecule ◽  
Sperm Whale Myoglobin

The complete amino acid sequence of human skeletal myoglobin is described. That of heart myoglobin is found by homology to be the same. When myoglobin is prepared some minor fractions may be obtained besides the main component. They are shown to be artefacts arising from deamidations. The likely three-dimensional structure of human myoglobin is discussed, taking that of sperm-whale myoglobin as a reference. Human myoglobin is compared with the α - and β -chains of human haemoglobin. There is a noteworthy similarity of internal residues and haem contacts, but little resemblance of sites where the haemoglobin chains form dimeric and tetrameric contacts, when they become subunits of the haemoglobin molecule.

scholarly journals Functional effects of heme orientational disorder in sperm whale myoglobin.

1987 ◽  
Vol 262 (1) ◽  
pp. 46-52
Author(s):  
W R Light ◽  
R J Rohlfs ◽  
G Palmer ◽  
J S Olson
Keyword(s):  
Sperm Whale ◽  
Orientational Disorder ◽  
Sperm Whale Myoglobin
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