Embryonic pig hemoglobins Gower I (ζ2ϵ2), Gower II (α2ϵ2), Heide I () and Heide II (): oxygen-binding functions related to structure and embryonic oxygen supply

Weber, Roy E.; Kleinschmidt, Traute; Braunitzer, Gerhard

doi:10.1016/0034-5687(87)90088-0

Cited by 20 publications

(14 citation statements)

References 21 publications

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“…Similarly, Cooper et al (1996) found only the adult pglobin and an embryonic /)-like &-gene. Thus, our results show more than one embryonic 8-like globin in a marsupial, which has been reported before in eutherian (placental) mammals such as the pig (Bieber and Braunitzer, 1984;Weber et al, 1987), and mouse and rabbit (Steinheider et al, 1975). In the Tammar, we found that the most abundant P-like c-chain was in three of the four Hb types (2, 3, and 4).…”

Section: Discussionsupporting

confidence: 88%

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Characterization of the Embryonic Globin Chains of the Marsupial Tammar Wallaby, Macropus Eugenii

Holland

Gooley

1997

European Journal of Biochemistry

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The embryonic hemoglobins of the marsupial Tammar wallaby (Macrop~s eugenii) are known to aggregate, which was shown by the finding that the Hill coefficient, h, was greater than 4.0 in the upper part of the oxygen equilibrium curve. Here, we have undertaken a detailed primary structure analysis of the Tammar wallaby pouch young hemoglobin complement, which we hoped might provide clues into the residues that cause aggregation and a high embryonic h.The Tammar wallaby embryonic hemoglobin complement is principally four major hemoglobins each with a different isoelectric point. Two early expressed hemoglobins contain the same embryonic p-like chain, epsilon ( E ) , but two separate n-like chains, termed zeta and zeta prime ([ and c) both of which are N-terminally blocked. The later two expressed hemoglobins contain the same adult u-chain, but different [Hike chains. The latest expressed hemoglobin contains the same b-like chain, e, as the two early expressed forms, but the third expressed hemoglobin contains a unique &like chain which we have termed omega (LO). A protein database similarity search using the first 54 N-terminal amino acids of the w-chain showed a range of sequence identities of 57-72% to all known mammalian /?-like chains, including the other marsupial c-chains. The closest identity, retlected by both the highest percentage identity and SmithWaterman score, was with the embryonic P-chains of the aves.While the primary structures of the hemoglobins reported here do not explain the low hemoglobinoxygen affinity in embryonic marsupial blood, the finding of the similarity with the bird globin-like sequence with one of the marsupial chains has implications on mammalian globin evolution. How many other marsupials and placental mammals are harboring a bird-like globin in their embryos'?

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Section: Discussionsupporting

confidence: 88%

“…affinity in embryonic Tammar blood has been found from the sequence data reported here. Weber et al (1987) believe that position 130 in the Q or ( chains is important for determining O2 affinity but our sequencing does not yet include this region.…”

Section: Discussionmentioning

confidence: 99%

Characterization of the Embryonic Globin Chains of the Marsupial Tammar Wallaby, Macropus Eugenii

Holland

Gooley

1997

European Journal of Biochemistry

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“…1977, Willford & Hill 1986). In the absence of DPG, at high pH (where proton binding is low), and at low (0.07 m m ) Cl − concentration, swine Hb exhibits high temperature sensitivity (−67 kJ mol −1 , corrected for Δ H H2O ) that is drastically reduced (to −14 kJ mol −1 at pH 7.4) by proton binding and the presence of DPG and Cl − ions (Weber et al. 1987b).…”

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confidence: 99%

Temperature dependence of haemoglobin–oxygen affinity in heterothermic vertebrates: mechanisms and biological significance

Weber¹,

Campbell²

2010

Acta Physiologica

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As demonstrated by August Krogh et al. a century ago, the oxygen-binding reaction of vertebrate haemoglobin is cooperative (described by sigmoid O(2) equilibrium curves) and modulated by CO(2) and protons (lowered pH) that - in conjunction with later discovered allosteric effectors (chloride, lactate and organic phosphate anions) - enhance O(2) unloading from blood in relatively acidic and oxygen-poor tissues. Based on the exothermic nature of the oxygenation of the haem groups, haemoglobin-O(2) affinity also decreases with rising temperature. This thermal sensitivity favours oxygen unloading in warm working muscles, but may become detrimental in regionally heterothermic animals, for example in cold-tolerant birds and mammals and warm-bodied fish, where it may perturb the balance between O(2) unloading and O(2) requirement in organs with substantially different temperatures than at the respiratory organs and thus commonly is reduced or obliterated. Given that the oxygenation of haemoglobin is linked with the endothermic release of allosteric effectors, increased effector interaction is an effective strategy that is widely exploited to achieve adaptive reductions in the temperature dependence of blood-O(2) affinity. The molecular mechanisms implicated in heterothermic vertebrates from different taxonomic groups reveal remarkable variability, both as regards the effectors implicated (protons in tunas, organic phosphates in sharks and billfish, chloride ions in ruminants and chloride and phosphate anions in the extinct woolly mammoth, etc.) and binding sites for the same effectors, indicating multiple evolutionary origins, but convergent physiological functionality (reductions in temperature dependence of O(2) -binding affinity that safeguard tissue O(2) supply).

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“…Assessment of the functional properties of isolated embryonic haemoglobins has been rather difficult as it requires substantial amounts of embryonic blood for preparation of the various haemoglobin fractions. Therefore, the oxygen binding properties of isolated embryonic haemoglobins have been analysed in detail only in a few species [51,53–55]. In the case of human embryonic haemoglobin, the technical problems of providing sufficient amount of protein have been solved by establishing either yeast cell culture expression systems [53,56] or by introducing human embryonic haemoglobin genes into a transgenic mouse model [54].…”

Section: Extracellular Signalsmentioning

confidence: 99%

“…On the other hand, the major embryonic haemoglobin fractions have a substantial affinity for organic phosphates, comparable to or even higher than that of adult haemoglobin [51,53–55], and normal to slightly reduced cooperativity of oxygen binding.…”

Section: Extracellular Signalsmentioning

confidence: 99%

Erythropoiesis and red cell function in vertebrate embryos

Baumann

Dragon

2005

Eur J Clin Investigation

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All vertebrate embryos produce a specific erythroid cell population--primitive erythrocytes--early in development. These cells are characterized by expression of the specific embryonic haemoglobins. Many aspects of primitive erythropoiesis and the physiological function of primitive red cells are still enigmatic. Nevertheless, recent years have seen intensive efforts to characterize in greater detail the molecular events underlying the initiation of erythropoiesis in vertebrate embryos. Several key genes have been identified that are necessary for primitive and the subsequent definitive erythropoiesis, which differs in several aspect from primitive erythropoiesis. This review gives in its first part a short overview dealing with comparative aspects of primitive and early definitive erythropoiesis in higher and lower vertebrates and in the second part we discuss the physiological function of primitive red cells based mainly on results from mammalian and avian embryos.

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Embryonic pig hemoglobins Gower I (ζ2ϵ2), Gower II (α2ϵ2), Heide I () and Heide II (): oxygen-binding functions related to structure and embryonic oxygen supply

Cited by 20 publications

References 21 publications

Characterization of the Embryonic Globin Chains of the Marsupial Tammar Wallaby, Macropus Eugenii

Characterization of the Embryonic Globin Chains of the Marsupial Tammar Wallaby, Macropus Eugenii

Temperature dependence of haemoglobin–oxygen affinity in heterothermic vertebrates: mechanisms and biological significance

Erythropoiesis and red cell function in vertebrate embryos

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