Showing papers on "Myoglobin published in 1980"

The antibody response to myoglobin is independent of the immunized species. Analysis in terms of replacements in the antigenic sites and in environmental residues of the cross-reactions of fifteen myoglobins with sperm-whale myoglobin antisera raised in different species.

Abstract: The recent determination of the entire antigenic structure of sperm-whale myoglobin with rabbit and goat antisera has permitted the examination of whether the antigenic structure recognized by antibodies depends on the species in which the antisera are raised. Also, by knowledge of the antigenic structure, the molecular factors that determine and influence antigenicity can be better understood in terms of the effects of amino acid substitutions occurring in the antigenic sites and in the environmental residues of the sites. In the present work, the myoglobins from finback whale, killer whale, horse, chimpanzee, sheep, goat, bovine, echidna, viscacha, rabbit, dog, cape fox, mouse and chicken were examined for their ability to cross-react with antisera to sperm-whale myoglobin. By immunoadsorbent titration studies with radioiodinated antibodies, each of these myoglobins was able to bind antibodies to sperm-whale myoglobin raised in goat, rabbit, chicken, cat, pig and outbred mouse. It was found that the extent of cross-reaction of a given myoglobin was not dependent on the species in which the antisera were raised. This indicated that the antibody response to sperm-whale myoglobin (i.e. its antigenic structure) is independent of the species in which the antisera are raised and is not directed to regions of sequence differences between the injected myoglobin and the myoglobin of the immunized host. Indeed, in each antiserum from a given species examined, that antiserum reacted with the myoglobin of that species. The extent of this auto-reactivity for a given myoglobin was comparable with the general extent of cross-reactivity shown by that myoglobin with antisera raised in other species. The cross-reactivities and auto-reactivities (both of which are of similar extents for a given myoglobin) can be reasonably rationalized in terms of the effects of amino acid substitutions within the antigenic sites and within the residues close to these sites. These findings confirm that the antigenicity of the sites is inherent in their three-dimensional locations.

Myoglobin in the heart ventricle of tuna and other fishes.

Abstract: The myoglobin content in the hearts of several fishes is positively correlated with the ecological physiology of the species. In the tuna heart, where the highest myoglobin values are found, the logarithmic relationship between myoglobin content and body weight is reported.

High-pressure proton nuclear magnetic resonance studies of hemoproteins. Pressure-induced structural change in heme environments of myoglobin, hemoglobin, and horseradish peroxidase.

Abstract: Hyperfine shifted proton NMR spectra of metmyoglobin, methemoglobin, and their complexes with azide, imidazole, and cyanide as well as the spectrum of native horseradish peroxidase were obtained at high pressures up to 2000 atm with a specially designed high-pressure cell for 220-MHz superconducting NMR spectrometer. For the azide complexes of metmyoglobin, in all of which the iron atoms are in thermal spin equilibrium between high- and low-spin states, the increased pressure shifted their heme methyl proton signals to the upfield side. For the cyanide complexes of metmyoglobin and methemoglobin and for the fluoride complex of metmyoglobin, which are in purely low- and high-spin states, respectively, the spectra were almost insensitive to changes in pressure up to 2000 atm. The heme methyl proton signals of aquometmyoglobin, its formate complex, and horseradish peroxidase showed appreciable upfield shifts upon pressurization. These results were interpreted to indicate that the primary effect of pressure on the hemoprotein structure is to shift the spin equilibrium in favor of the low-spin form. Hemichrome formation of methemoglobin at high pressures was also observed, and the effect of pressure on the heme environmental structure of deoxyhemoglobin and deoxymyoglobin was also discussed.

Heme pigment content of bovine hemopoietic marrow and muscle

Abstract: Hemopoietic marrow from the cervical and lumbar vertebrae and muscle adjacent to the vertebrae of four veal, four steers, and four cows were analyzed for total pigment, hemoglobin, myoglobin, and iron. Total pigment, hemoglobin, and iron were higher in marrow than in muscle. Hemoglobin and iron content of marrow remained relatively constant with increasing age while myoglobin and iron content of muscle doubled in steers and tripled in cows when the values were compared to those of veal. Pigment and iron interactions for age times location occurred because marrow from the lumbar vertebrae became fatter sooner than marrow from cervical vertebrae. Storing muscle or marrow 1-wk at 2°C or freezing muscle or marrow at -29°C for 60 days prior to analyses did not change total pigment concentration or hemoglobin and myoglobin percentages in tissue. Mechanically processed beef product (MPP) is a mixture of muscle and marrow and the amount of total pigment increases as the amount of hemoglobin from marrow increases. Therefore, total pigment determination offers a simple method for estimating marrow content of MPP provided constant total pigment values for muscle and marrow by age of animals and by anatomical location can be established.

Freezing induced change in ligand orientation in oxycobalt-myoglobin

Abstract: Single crystals of oxycobalt-myoglobin were examined by electron paramagnetic resonance (EPR) spectroscopy at ambient and cryogenic temperatures. The principal values and eigenvectors of the g-tensor and the hyperfine coupling tensor were determined. The Co—O—O bond angle was estimated to be 125° at ambient temperature. The single crystal EPR data of oxycobalt myoglobin at 77 K showed two sets of the principal values for g and hyperfine coupling tensors and eigenvectors, indicating that the bound oxygen molecule takes two distinct orientations. The result has demonstrated for the first time that the well defined change in the molecular orientation is induced upon freezing the biological macromolecule.

Evolution of the amino acid substitution in the mammalian myoglobin gene.

Abstract: Multivariate statistical analyses were applied to 16 physical and chemical properties of amino acids. Four of these properties; volume, polarity, isoelectric point (charge), and hydrophobicity were found to explain adequately 96% of the total variance of amino acid attributes. Using these four quantitative measures of amino acid properties, a structural discriminate function in the form of a weighted difference sum of squares equation was developed. The discriminate function is weighted by the location of each particular residue within a given tertiary structure and yields a numerical discriminate or difference value for the replacement of these residues by different amino acids. This resulting discriminate value represents an expression of the perturbation in the local positional environment of a protein when an amino acid substitution occurs. With the use of this structural discriminate function, a residue by residue comparison of the known mammalian myoglobin sequences was carried out in an attempt to elucidate the positions of possible deviations from the known tertiary structure of sperm whale myoglobin. Only 11 of the 153 residue positions in myoglobin demonstrated possible structural deviations. From this analysis, indices of difference were calculated for all amino acid exchanges between the various myoglobins. All comparisons yielded indices of difference that were considerably lower than would be expected if mutations had been fixed at random, even if the organization of the genetic code is taken into consideration. On the basis of these results, it is inferred that some form of selection has acted in the evolution of mammalian myoglobins to favor amino acid substitutions that are compatible with the retention of the original conformation of the protein.

Differentiation of myoglobin and hemoglobin in biological fluids

Abstract: The use of several methods to differentiate myoglobin from hemoglobin has been investigated. The immunochemical methods, particularly those of hemagglutination inhibition and radioimmunoassay, are the most useful. This report summarizes work in the Ames Research Laboratory over the past 17 years with the several methods.

Structure and mechanism of liver alcohol dehydrogenase, lactate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase.

Abstract: In 196 Michael Rossmann, Herman Watson and Carl Branden in the Cambridge laboratory of Max Perutz and John Kendrew occasionally discussed future crystallographic projects which might illuminate structure — function relationships within families of proteins. At that time the structure of myoglobin had been determined to high resolution and that of haemoglobin to low resolution. A small number of additional studies of monomeric protein molecules were at the low resolution stage but very little work had been started on larger oligomeric enzyme molecules.

Characterization of the hemoglobins and myoglobin of Travisia foetida

Abstract: 1. 1. Travisia foetida has an extracellular vascular hemoglobin, a coelomic cell hemoglobin and a body wall myoglobin which are chemically distinct from one another. 2. 2. The vascular hemoglobin is a 3.4 × 10 6 mol. wt molecule consisting of at least four different subunits with molecular weights ranging from 15–18,000 and has one heme group per 23,400 g protein. 3. 3. The coelomic cell hemoglobin is a 32,000 mol. wt dimeric protein with subunits of molecular weight 16,000. The hemoglobin is homogeneous on isoelectric focusing with a pI = 8.6–8.8. 4. 4. The body wall myoglobin is a 30,000 mol. wt dimeric protein with subunits of molecular weight 15,000. It is also electrophoretically homogeneous with a pI = 6.9. 5. 5. The amino acid compositions of these three purified proteins are presented and are quite different from one another. 6. 6. All three pigments lack a Bohr effect and their relatively high oxygen affinities are such that myoglobin > coelomic cell hemoglobin > vascular hemoglobin. Both the coelomic cell hemoglobin and the myoglobin show slightly cooperative oxygen binding consistent with their dimeric quaternary structure.

Effect of postmortem electrical stimulation on bovine myoglobin and its derivatives

Abstract: Zone electrophoresis using cellulose acetate membrane as the supporting medium was developed as a method to measure the amount and quantitate myoglobin and its derivatives. Total pigment and total myoglobin concentrations were not affected by electrical stimulation, but different animals and different muscles did influence the total pigment and total myoglobin content. Muscle which had been electrically stimulated showed an increase in oxymyoglobin content. This result was supported by a visual appraisal. Results from visual appraisal also supported the finding that metmyoglobin was lower in both the control and stimulated samples. The electrically stimulated steaks were bright red in color while the control samples were dark purplish red.

Myoglobins of cartilaginous fishes. II. Isolation and amino acid sequence of myoglobin of the shark Mustelus antarcticus.

Abstract: Myoglobin isolated from red muscle of the gummy shark M. antarcticus was purified by gel filtration and ion-exchange chromatography on carboxymethyl cellulose in 8 M urea-thiol buffer. Amino acid analysis and sequence determination showed 148 amino acid residues. The amino terminal residue is acetylated as shown by nuclear magnetic resonance and mass spectrographic analysis of an N-terminal peptide. There is a deletion of four residues at the amino terminal end as well as one residue in the CD interhelical area relative to other myoglobins. These overall differences were also found previously in myoglobin of Heterodontus portusjacksoni.

Structural significance of the amino-terminal residues of sperm whale myoglobin.

Abstract: Following the development of a nondestructive synthetic procedure for rapid production of des-Val1-myoglobin in large quantities, the synthesis of a series of myoglobin derivatives varying in structure and charge in the NH2-terminal region was accomplished. In comparison to the untreated myoglobin, the des-Val1-myoglobin was found to possess at low pH a decreased stability and an increased net positive charge in the pH range 5.5-8.5. While the elevated net positive charge was no longer apparent after removal of the second residue, the instability of the molecule was found to be sharply increased. Substitutions of the first residue, directed toward elucidating its structural importance, included glutamic acid, lysine, and glycine. Addition of any of the three amino acids to the des-Val1-myoglobin was found to restore much of the acid stability, with the [Gly1]myoglobin appearing nearly identical with the native molecule. All three semisynthetic myoglobins showed potentiometric titration curves characteristic of their respective, substituted residue. Carbamylation of the NH2 terminal of myoglobin and des-Val1-myoglobin yielded two nearly identical molecules in terms of all physical properties examined. Consequently, it was concluded that the first residue primarily serves the function of maintaining the positively charged NH2 terminus a certain distance away from the beginning of the A helix and from the charge pair interaction of Lys-133 with Glu-6. In addition, through physical measurements of the des-Val1,Leu2-myoglobin prior and subsequent to carbamylation of the NH2 terminus, it was apparent that the stabilization conferred on the des-Val1-myoglobin by the second residue was dependent to a large degree upon the hydrophobic interactions of its side chain.

Serum concentrations of myoglobin, creatine kinase, lactate dehydrogenase and cardiac isoenzymes in euthyroid, hypothyroid and hyperthyroid subjects.

Abstract: Serum concentrations of myoglobin, creatine kinase and lactate dehydrogenase were measured in 33 euthyroid, 21 hyperthyroid and 15 hypothyroid subjects. The results showed that myoglobin, creatine kinase and lactate dehydrogenase were increased and decreased in the hypoand hyperthyroid states, respectively. In addition, the concentrations of myoglobin, creatine kinase and lactate dehydrogenase values were inversely related to both the thyroxine and triiodothyronine concentrations. To study the origin of the increased muscle protein values observed in hypothyroidism, the cardiac isoenzyme fractions were measured; the results obtained support the view that the muscle enzymes are mainly derived from skeletal muscles.