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Showing papers on "Myoglobin published in 1970"



Journal ArticleDOI
TL;DR: This work shows that it is possible to prepare and study a cobalt-substituted hemoglobin-a coboglobin (Cb) and that this reconstituting metalloprotein exhibits reversible oxygen binding, and investigates the relationship of the metal atom and metaloxygen binding to such characteristics of the nature proteins as cooperative oxygen uptake.
Abstract: In this work we show that it is possible to prepare and study a cobalt-substituted hemoglobin—a coboglobin (Cb).—and that this reconstituted metalloprotein exhibits reversible oxygen binding. The effect of the protein environment on Co(II)-protoporphyrin IX is directly observed by esr measurements on deoxy- and oxy-Cb and by oxygen uptake measurements, all of which may be compared with similar measurements on the free metalloporphyrin. Reversing our point of view, we compare oxygen binding to Cb with that of hemoglobin, and thus investigate the relationship of the metal atom and metaloxygen binding to such characteristics of the nature proteins as cooperative oxygen uptake.

219 citations


Journal ArticleDOI
R.G. Shulman1, Kurt Wüthrich1, T. Yamane1, Dinshaw J. Patel1, William E. Blumberg1 
TL;DR: Differences in the ring-current-shifted resonances amongst various ligated forms including cyanoferrimyoglobin, indicate the existence of structural differences in the protein when the ligand is changed.

87 citations


Journal ArticleDOI
TL;DR: The covalent structure of beef myoglobin is being investigated through different experimental approaches through tryptic and chymotryptic digestions and the complete amino acid sequence of these peptides has been established.
Abstract: The covalent structure of beef myoglobin is being investigated through different experimental approaches. The globin was cleaved by cyanogen bromide. The resulting fragments were fractionated and submitted to tryptic and chymotryptic digestions. The complete amino acid sequence of these peptides has been established. From the overlaps in sequence between chymotryptic and tryptic peptides, it is possible to place most of these peptides of 153 residues of beef myoglobin in unique sequence. The remaining residues have been ordered on the basis of the apparent homology in sequence between beef and horse myoglobins. The horse protein differs from that of beef in 18 positions. All of the amino acid replacements, except three, were confined to amino acid interchange caused by the change of one base in the coding triplet leaving 135 of 153 positions in the sequence invariant in the two proteins. The relations of these data to other is discussed.

79 citations


Journal ArticleDOI
TL;DR: One of the early responses to overload appears to be increased synthesis of myosin while collagen and myoglobin synthesis seems to be unchanged.
Abstract: SCHREIBER, SIDNEY S., MURRAY ORATZ, CAROLE D. EVANS, IDA GUEYIKIAN, AND MARCUS A. ROTHSCHILD. Myosin, myoglobin, and collagen synthesis in acute cardiac overload. Am. J. Physiol. 2 19(2) : 481-486. 1970.-Acute cardiac overload rapidly leads to increased protein synthesis seen in subcellular systems with microsomes as well as in total ventricular protein isolated from stressed left ventricles. The type of protein involved in the early response was studied separately in the guinea pig in the intact isolated perfused heart with measurements of lysine-14C incorporation into myosin and myoglobin, and with the conversion of proline-14C into hydroxyproline14C as a measure of collagen synthesis. After 3 hr of increased aortic pressure and increased left ventricular contractile activity, total ventricular protein from overloaded left ventricles showed increased incorporation of labeled lysine. However, myoglobin incorporation of lysineJ4C was no greater than the control, whereas myosin showed significant increase. Similarly, although proline14C incorporation was increased in total left ventricular protein from overloaded ventricles, conversion to hydroxyproline14C was not consistently different from controls. Thus, one of the early responses to overload appears to be increased synthesis of myosin while collagen and myoglobin synthesis appears to be unchanged.

59 citations


Journal ArticleDOI
TL;DR: The fractional distribution of blood flow was measured by the isotope dilution method and absolute blood flow estimated in twenty‐four muscles of chronically prepared, unanaesthetized cats.
Abstract: 1. The fractional distribution of blood flow was measured by the isotope dilution method and absolute blood flow estimated in twenty-four muscles of chronically prepared, unanaesthetized cats. 2. In the quiet, alert cat the estimated mean muscle blood flow ranged from 5·9 to 39·3 ml./min 100 g muscle. Flow was three times greater in grouped red than white limb muscles. 3. The myoglobin concentration ranged from 0·88 to 3·91 mg/g muscle. The myoglobin concentration of grouped red exceeded that of white muscle and varied in each muscle directly and linearly with blood flow with a high correlation (P < 0·001). 4. Capillary density was estimated by determination of alkaline phosphatase activity. Alkaline phosphatase activity was significantly greater in red than white muscles and varied directly with fractional blood flow in these same muscles with a high correlation (P < 0·001). 5. Contraction time was generally two to three times longer in red than white muscle. There was a direct and highly correlated relationship (P < 0·001) between blood flow and contraction time. 6. The direct linear relationship between muscle blood flow and myoglobin concentration, capillary density, and contraction time characteristic of quiet wakefulness was lost during rapid eye movement sleep or excitement produced by electrical stimulation of the hypothalamus as a consequence of selective changes in flow in red and white skeletal muscle. 7. The type of metabolism of any skeletal muscle is adapted to its activity during quiet, alert behaviour, rather than during sleep or excitement.

49 citations



Journal ArticleDOI
TL;DR: Crystals of sperm whale ferrimyoglobin treated with 0.2 m sodium bromoacetate in concentrated ammonium sulfate solution at pH 6.8 retained most of the physical properties of the unmodified protein, except for the development of a small number of electrophoretic components.

37 citations


Journal ArticleDOI
TL;DR: Xenon absorption by myoglobin at various temperatures and pressures is presented, presenting evidence for HpXe formation.
Abstract: Xenon absorption by myoglobin at various temperatures and pressures, presenting evidence for HpXe formation

34 citations


Journal ArticleDOI
TL;DR: In oxymyoglobin and myoglobin, the resonances of the NH protons of the two tryptophans are observed, as well as one resonance from arginine and one from histidine in the range -10 to -15 ppm downfield from 3-(trimethylsilyl)propanesulfonic acid (sodium salt).
Abstract: Exchangeable hydrogens in proteins can be identified by comparison of nuclear magnetic resonance spectra obtained in H2O and in D2O. In oxymyoglobin and myoglobin we have been able to observe resonances of the NH protons of the two tryptophans, as well as one resonance from arginine and one from histidine in the range -10 to -15 ppm downfield from 3-(trimethylsilyl)propanesulfonic acid (sodium salt). These resonances have been identified by chemical modifications coupled with considerations of crystallographic structure and the dependence of the resonances on the species (sperm whale, porpoise, horse) from which the myglobin was obtained and on spin, pH, and temperature.

25 citations


Journal ArticleDOI
TL;DR: The spectroscopic characteristics of ferro- and ferrisulphhaemoglobin coordination complexes have been defined and are reported, and features of interest include the formation of a carbonmonoxy-cyano ferro complex, which seemingly requires six coordination positions, thus excluding the globin histidine.

Journal ArticleDOI
TL;DR: A comparison of the properties of the preparations indicated that Sepharose-myoglobin was superior, as an immunoadsorbent, to the other conjugates.
Abstract: Immunoadsorbents that were potentially suitable for the fractionation of antibodies to myoglobin were prepared by coupling myoglobin to aminoethylcellulose, bromoacetylcellulose, CM-cellulose, an ethylene–maleic anhydride co-polymer and Sepharose 4B. A comparison of the properties of the preparations indicated that Sepharose–myoglobin was superior, as an immunoadsorbent, to the other conjugates. Elution of adsorbed antibodies with m-propionic acid, pH2.5, gave yields of precipitable antibody higher than those achieved with other dissociating solvents. Propionic acid eluted 60–100% of the antibody adsorbed by Sepharose–myoglobin, and 60–90% of the eluted protein was precipitable antibody.


Journal ArticleDOI
TL;DR: In this article, reflectance spectroscopy of the haem compounds of turkey breast and leg muscle showed that the structure of the main component, myoglobin, changed during the freeze-drying process to form a low-spin complex, ferromyochromagen.
Abstract: A study by reflectance spectroscopy of the haem compounds of turkey breast and leg muscle showed that the structure of the main component, myoglobin, changed during the freeze-drying process to form a low-spin complex, ferromyochromagen. Ferrimyoglobin, either present in fresh muscle or introduced as an oxidation product during dehydration, forms the corresponding ferrimyochromagen. During storage in the freeze-dried state the iron complexes do not catalyse the autoxidation of unsaturated lipids. When freeze-dried muscle is rehydrated to a water content not less than 50% of that of fresh muscle, a proportion of the haem pigment is present in the form of a high-spin complex, metmyoglobin, which catalyses autoxidation of unsaturated lipids in the rehydrated muscle.

Journal ArticleDOI
TL;DR: No myoglobin was detectable in extracts from human uterus and taenia coli muscle by reaction with antibody against purified human skeletal muscle myoglobin, and with Sephadex gel chromatography and starch gel electrophoresis no protein corresponding to this myoglobinwas found in human smooth muscle extracts.
Abstract: No myoglobin was detectable in extracts from human uterus and taenia coli muscle by reaction with antibody against purified human skeletal muscle myoglobin. With Sephadex gel chromatography and starch gel electrophoresis no protein corresponding to this myoglobin was found in human smooth muscle extracts. The immunological procedure employed would have detected a concentration of skeletal muscle myoglobin as low as 0.001 mg/g of muscle wet weight.

Journal ArticleDOI
TL;DR: Comstrol experiments employing the biochemical technique of emizymatic imshibition at low pH confirm that the presence of the precipitate its the endoplasmic reticuhttm is more probably related to glucose 6-phosphatase activity.
Abstract: 1 This research was supported ims part by Public Health Service Research Graust FD-00107-11. in the liver (Okaji. Folia Anat. Jap. 44: 11. 1967). Moreover, the intensity of the reaction follows the biochemical flnsdimsgs of Ockerman (Biochirn. Biophys. Acta 105: 22. 1965) and our own results (D. Maestracci. unpublished observation). The precipitate, indeed, is more abundant in the jejunium than its the duodenum or ins the ileu,m. Comstrol experiments employing the biochemical technique of emizymatic imshibition at low pH confirm that the presence of the precipitate its the endoplasmic reticuhttm is more probably related to glucose 6-phosphatase activity. With glycerophosphate as substrate, the positivity of the brush border, multivesicular and demise bodies seems to prove that other phosphatases, probably alkaline and acid phosphatase, are respomssihle for this localization (Hutgon, J. and Borgers, M. Histochemie 12: 42. 1968). For thyamine pyrophosphatase activity our results confirm the preceding work of Goldfisher, Essner and Novikoff (J. Histochem. Cytoc/tern. 12: 72. 1964), but perhaps the eusdoplasmic localization is more obvious.


Journal ArticleDOI
TL;DR: Even though the mechanisms for urea denaturation of myoglobin and apomyoglobin differ, both systems were characterized by the operation of a series of reactions which produce several forms of denatured proteins.

Journal ArticleDOI
TL;DR: It is shown that reversibility depended strongly on the ionization of the amino acid residues lying on the surface of the protein molecule and probably associated in “cluster groups”, and the specific effect of tyrosyl groups on the mechanism of reversibility is discussed.

Journal ArticleDOI
TL;DR: It is shown that proton relaxation, as well as other spin-label methods, can be highly sensitive for studying small-scale conformational changes in protein molecules.

Journal ArticleDOI
TL;DR: Chick embryos and their isolated body parts were capable of myoglobin synthesis, when measured with anin vitro system using incorporation of lysine-U-14C into precipitates formed with specific antimyoglobin serum, most strikingly between age 2 and 4 daysin ovo.

Journal ArticleDOI
TL;DR: The determination of the X-ray crystal structure of erythrocruorine from Chironomus thummi shows that its tertiary structure is very similar to that of sperm whale myoglobin.
Abstract: The determination of the X-ray crystal structure of erythrocruorine from Chironomus thummi shows that its tertiary structure is very similar to that of sperm whale myoglobin. Significant differences were, however, observed in the neighbourhood of the haem group. Seven phenylalanines give the haem pocket of erythrocruorine an aromatic character. The distal amino acid residue closest to the haem iron is the unpolar isoleucine E 11 instead of the polar histidine E 7 in myoglobin. In Spite of these differences the oxygen affinity curves of crystallisable Chironomus thummi erythrocruorine and vertebrate myoglobin are virtually identical.


Journal ArticleDOI
TL;DR: The radular muscle myoglobin of Littorina littorea has been purified and is cleaved into monomeric subunits by p-hydroxymercuribenzoate (PMB), which is electrophoretically homogeneous on acrylamide gels.


Journal ArticleDOI
TL;DR: Presents the design details for constructing three dimensional models of proteins, including myoglobin and lysozyme, as well as their applications in medicine and materials science.
Abstract: Presents the design details for constructing three dimensional models of proteins, including myoglobin and lysozyme.


Book ChapterDOI
TL;DR: It is suggested that 2, 3-DPG is bound in the central cavity of hemoglobin, and there are two amino acid differences between the β-chains and γ-chains in this region of the molecule, and it may be these that affect the binding of 2,3- DPG.
Abstract: Publisher Summary This chapter elaborates the molecular changes in hemoglobin during development and their functional significance. In the mammalian developmental hemoglobin studied, the difference between various types is always in the non-α-chains, while α-chain is found at all stages except when hemoglobin synthesis first starts. This finding may be relevant to the position of the binding site for 2, 3-DPG on the molecule. It has been shown that Hb-β4 binds 2, 3-DPG, while Hb-α does not. This finding suggests that the binding site is only present on the β-chain. It is suggested that 2, 3-DPG is bound in the central cavity of hemoglobin. There are two amino acid differences, G-6 ARN → LYS and H-21 HIS → SER, between the β-chains and γ-chains in this region of the molecule, and it may be these that affect the binding of 2, 3-DPG. The N-terminal residue that is in the β–β contact is also different in the two chains

Journal ArticleDOI
TL;DR: It is postulated that animals rearing in alternating temperatures experienced intermittent and persistent development of tissue hypoxia and, as a consequence, had reduced aerobic metabolic pathways in muscle as compared to animals reared in constant ambient temperatures.
Abstract: SUMMARY Animals reared in constant ambient temperatures had significantly more skeletal muscle myoglobin than those reared in alternating temperature environments when the humidity was moderate or high. These differences did not exist when humidity levels were low. Comparisons ofthe effect of humidity level in constant ambient temperatures revealed high myoglobin in pigs subjected to moderate as compared to low humidity at 27°C, but humidity effects were nonexistent when the ambient temperature was 21 or 32° C. It is postulated that animals reared in alternating temperatures experienced intermittent and persistent development of tissue hypoxia and, asa consequence, had reduced aerobic metabolic pathways in muscle as compared to animals rearedinconstant ambient temperatures.

Journal ArticleDOI
TL;DR: Aromatic compounds like chlorpromazine and benzoate and its homologs strongly enhance the rate of heat denaturation of myoglobin by complexing with a single kind of site in the hemeprotein.