Dder einfluss von liganden auf den assoziationsgrad des desoxy‐hämoglobins der flussneunaugen (<i>lampetra fluviatilis</i> L.)

Behlke, Joachim; Scheler, W

doi:10.1016/0014-5793(70)80150-8

Cited by 21 publications

(7 citation statements)

References 5 publications

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“…Furthermore, oligomeric forms of hemoglobin from the lamprey Lampetra fluviatilis exist under two conditions that differ significantly. In the absence of oxygen and in solutions of pH below 7.0, lamprey hemoglobin forms dimers and perhaps tetramers (25). The ligation of oxygen causes the dissociation of oligomers.…”

Section: Resultsmentioning

confidence: 99%

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Molecular models for the putative dimer of sea lamprey hemoglobin.

Honzatko¹,

Hendrickson²

1986

Proc. Natl. Acad. Sci. U.S.A.

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The known structures for the tetramers of mammalian and clam hemoglobins provide a point of departure for the modeling of putative dimers of lamprey hemoglobin. The association of subunits is dissimilar for the clam and mammalian tetramers; the superposition of the molecular model for lamprey methemoglobin onto the mammalian and clam tetramers gives five distinct dimers. After energy minimization of the interface regions of the five models, three models afford promising interactions between side chains. One model is analogous to the al.f2 pairing of subunits of mammalian hemoglobins. The other two models are similar to the interfaces between the E and F helices and between the A and B helices of clam hemoglobin. Although the model based on the alf2 mode of association provides the best explanation of biochemical properties of lamprey hemoglobin, such as the Bohr effect and the dependency of dimer formation on pH, interfaces between the E and F and the A and B helices could be important in the aggregation of monomers of lamprey hemoglobin beyond the level of the dimer.Cooperative phenomena of vertebrate hemoglobins evolved some 500 million years ago over a relatively brief span of 25-50 million years. On the basis of work by Goodman et al.(1), the ancestral globin of the sea lamprey represents the earliest stage in the evolution of the present day tetramer. As fossil records reveal little change in the morphology ofthe sea lamprey (2), the properties of the hemoglobin of modem-day sea lamprey (Petromyzon marinus) may be representative of those of the ancestral globin. The globins of sea lamprey are primarily monomeric. However, as the pH falls below 7.0, hemoglobins of the lamprey aggregate (3). The precise nature of the aggregated state(s) of lamprey hemoglobin is unclear, although much evidence exists for at least a dimer. Thermodynamically coupled to the aggregation phenomenon is the uptake of protons and the release of oxygen. Monomeric lamprey hemoglobin has a greater affinity for oxygen than do the aggregates. Thus, as lamprey hemoglobin accepts oxygen, the monomer-oligomer equilibrium shifts in favor of the monomer. Further, the transition from oligomer to monomer releases protons, a phenomenon analogous to the Bohr effect of mammalian hemoglobins.The superposition of monomers of lamprey hemoglobin onto the subunits of the mammalian and clam (Scapharca inaequivalvis) tetramers provides five distinct models of the putative dimer of lamprey hemoglobin. Only the models analogous to the a1/32 interface of the mammalian tetramer and to the E-F and A-B interfaces of the clam tetramer are possible for lamprey hemoglobin. The lamprey "a1/32" interface not only bears close resemblance to its mammalian counterpart, consistent with the notion that lamprey hemoglobin is an evolutionary precursor of the cooperative tetramer, but also provides explanations for the Bohr effect, the dependence of aggregation on pH, and the cooperative interactions during the uptake of oxygen by the dimer. However, either the E-F o...

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Section: Resultsmentioning

confidence: 99%

“…Cooperative phenomena of vertebrate hemoglobins evolved some 500 million years ago over a relatively brief span of 25-50 million years. On the basis of work by Goodman et al (1), the ancestral globin of the sea lamprey represents the earliest stage in the evolution of the present day tetramer.…”

mentioning

confidence: 99%

Molecular models for the putative dimer of sea lamprey hemoglobin.

Honzatko¹,

Hendrickson²

1986

Proc. Natl. Acad. Sci. U.S.A.

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“…Although self-association of deoxy lamprey Hbs to tetramers does occur (8,11,13), the 5 and 15 M (heme) concentrations used in the present experiments preclude significant effects of higher-order association. Doi et al (13) calculated the monomer-dimer and dimer-tetramer association constants to be 8.1 ϫ 10 4 M Ϫ1 and 6.5 ϫ 10 3 M…”

Section: Methodsmentioning

confidence: 67%

Lamprey Hemoglobin

Yang

Maillett

Knapp

et al. 2000

Journal of Biological Chemistry

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Lampreys and hagfish, the most primitive living vertebrates, have hemoglobins (Hbs) 1 distinct from those of all others in the class. Indeed, the low isoelectric points of the Hbs caused Svedberg and Eriksson (2) to identify them with invertebrate Hbs for which they had revived the term erythrocruorin.2 They found the Hbs to be monomeric, like myoglobins, rather than the tetramers characteristic of other vertebrates. However, Wald and Riggs (6) found that oxygen equilibria of lamprey (Petromyzon marinus) Hb were strongly pH-dependent (Bohr effect), a surprising result at the time because oxygen equilibria of the monomeric myoglobins were pH-independent. Furthermore, they found that the oxygen equilibrium at pH 6.8 was slightly cooperative, with a Hill coefficient of 1.2, but dismissed this result as an artifact because cooperativity is impossible with monomeric Hbs. Briehl (7) resolved this paradox by showing that deoxygenated lamprey Hb self-associates. Protonation accompanying the association accounts for the Bohr effect of O 2 binding. Behlke and Scheler (8) showed with sedimentation velocity measurements that ligated Hb from a similar species of lamprey (Lampetra fluviatilis) also self-associates, but only at low pH. Although the metHb was found to be monomeric, addition of metHb ligands such as azide or cyanide causes dimer formation at low pH (9). This property, oxidationinduced dissociation and ligand-dependent reassociation, absent in other vertebrate Hbs, but found in the Hbs of organisms of five invertebrate phyla, is another indication of the functional relationship of lamprey and invertebrate Hbs (10). Andersen and Gibson (11,12) showed by kinetic analysis of ligand binding by the Hb of P. marinus that the results could be accurately described by a model in which protonation of a single site per monomer with pK ϭ 6.0 accompanied the formation of dimers of low O 2 affinity. There was no need to include self-association beyond the dimer, so they concluded that higher aggregates may not be physiologically important. This conclusion was reinforced by sedimentation equilibria of the deoxy-Hb which indicated only very weak dimer-tetramer association. However, the conclusion that tetramers are physiologically insignificant was based on extrapolation of kinetic and sedimentation measurements at 10 -60 M concentration to millimolar concentrations. Dohi et al. (13) extended the sedimentation measurements to concentrations of 3 mM with Hb from another species of lamprey, Entosphenus japonicus. Their results suggested that as much as 85% of the deoxy-Hb within red cells of this species would be tetrameric. The amino acid composition (13) of E. japonicus globin is virtually identi-

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“…Es liegt als DesoxyHb dimer md oligomer vor und dissoziiert bei Bindung von 0, weitgehend in seine monomeren Einheiten. CO verhiilt sich an FluBneunaugen-Hb grundsLitzlich iihnlich wie 0, [8].…”

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“…Es liegt als Desoxy-Hb dimer md oligomer vor und dissoziiert bei Bindung von 0, weitgehend in seine monomeren Einheiten. CO verhiilt sich an FluBneunaugen-Hb grundsLitzlich iihnlich wie 0, [8]. Die Sedimentationskoeffizienten bestimmten wir mit einer analytischen Ultrazentrifuge G 110 von MOM Budapest [14] und einer U 50 L der Fa.…”

unclassified

Zur Wirkung von Liganden auf das Assoziations‐Dissoziations‐Gleichgewicht des Methämoglobins der Flußneunaugen (Lampetra fluviatilis L.)

Behlke

Scheler

1970

European Journal of Biochemistry

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The dissociation-association equilibrium of lamprey methemoglobin as a function of protein concentration, pH, and ligandation of the heme Fe3+ has been studied using sedimentation analysis.The sedimentation constant s ;~,~ of MetHb in the pH range 4.5 < pH < 10 amounts to 1.94 S leading to a calculated molecular weight of 17000 which corresponds to the Hb protomer.At pH 7.5 the MetHb * N, complex is monomeric. Below pH 5.7 and a t high protein concentration the dimer of 34000, s ;~,~ = 3.13 S, is formed, the dimerization being accompanied by an uptake of two protons per protomer : (a) (1)

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Dder einfluss von liganden auf den assoziationsgrad des desoxy‐hämoglobins der flussneunaugen (lampetra fluviatilis L.)

Cited by 21 publications

References 5 publications

Molecular models for the putative dimer of sea lamprey hemoglobin.

Molecular models for the putative dimer of sea lamprey hemoglobin.

Lamprey Hemoglobin

Zur Wirkung von Liganden auf das Assoziations‐Dissoziations‐Gleichgewicht des Methämoglobins der Flußneunaugen (Lampetra fluviatilis L.)

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