Functional properties of hemoglobin pôrto alegre (α2Aβ29 Ser→Cys) and the reactivity of its extra cysteinyl residue

Tondo, C. V.; Bonaventura, Joseph; Bonaventura, Celia; Brunori, Maurizio; Amiconi, Gino; Antonini, Eraldo

doi:10.1016/0005-2795(74)90101-9

Cited by 46 publications

(11 citation statements)

References 13 publications

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“…Since in PCD8(49) (an external position) a reactive Cys has replaced Ser or Tyr (commonly found in other fish hemoglobins), polymers are formed via intermolecular disulfide bridges between p chains, similar to the human variant PBrto Alegre (Tondo et al, 1974). Polymerisation does not affect oxygen binding.…”

Section: Structurelfunction Relationshipmentioning

confidence: 99%

A polymerising Root‐effect fish hemoglobin with high subunit heterogeneity

Fago¹,

Romano²,

Tamburrini³

et al. 1993

European Journal of Biochemistry

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The blood of the teleost Chelodunichthys kumu, living in the temperate waters of New Zealand, contains a single hemoglobin. The complete amino acid sequence of the a and / 3 chain has been established. The presence of a reactive Cys in the external position /3CD8(49) causes polymerisation through intermolecular disulfide bridges between p chains, with no alteration of functional features.C. kumu Root-effect hemoglobin displays very low or no subunit co-operativity in the physiological pH range. Kinetic experiments on the oxygen dissociation and binding of carbon monoxide show a marked, pH-dependent functional heterogeneity of the two chains, which contributes to the observed reduction of co-operativity. In contrast, kinetic heterogeneity was not observed in the process of CO dissociation, indicating that functional differences between the subunits are detectable only for the dynamic ligand association pathway. The allosteric effector, ATP, seems to increase the pK, of the proton-linked effect on the slow-reacting subunit, affecting the quaternary equilibrium through stabilisation of the T state at lower pH, rather than enhancing the functional heterogeneity itself. In position Ell of both chains, Val (usually present at the distal side of the heme), is substituted by Ile. Although this residue has been shown not to significantly alter ligand binding to the a chain, to some extent it can perturb the access of oxygen to the p chain. Thus, this substitution may be the main reason for subunit functional heterogeneity.The study of fish hemoglobins over the past years has revealed a wide range of different structural and functional properties, often associated with the multiplicity of components present in individual animals. Consequently, the regulation of oxygen binding on a structural basis cannot be interpreted generally and oxygen binding of individual hemoglobins may be the result of different molecular interactions.In several fish hemoglobins, a large reduction in the oxygen affinity and co-operativity is observed at low pH values (and in the presence of allosteric effectors), so that these hemoglobins cannot be fully saturated even with pure oxygen at pressures of several Pascalles (Scholander and Van Dam, 1954;Brunori et al., 1978). According to the interpretation of this effect (called the Root effect) in the framework of the two-state model of Monod et al. (1965), the T-R equilibrium is shifted by protons and/or other allosteric effectors towards the low-affinity conformation, thereby inhibiting the ligandlinked quaternary transitions and abolishing the co-operativity. Under these conditions, the Hill coefficient may drop to values d 1 .O, if associated to a subunit functional heterogeneity. A stereochemical interpretation of the Root effect was proposed by Perutz and Brunori (1982), who suggested that a few residues of the chain might be responsible for a relative stabilisation of the T state with respect to the R state. Although some Hb A mutants (Nagai et al., 1985;Luisi and Nagai, 1986) and Antarctic fi...

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Section: Structurelfunction Relationshipmentioning

confidence: 99%

A polymerising Root‐effect fish hemoglobin with high subunit heterogeneity

Fago¹,

Romano²,

Tamburrini³

et al. 1993

European Journal of Biochemistry

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“…Genetic variation in mouse beta globin is associated with variation in erythrocyte redox status caused by heterogeneity in the number and reactivity of beta globin cysteine sulfhydryl groups [7,8]. Human populations are not subject to this redox variation because with rare exception all human beta globins contain only one reactive cysteine residue (two rare di-cysteinyl exceptions include Hb Rainier (Tyr145Cys) [9] and Hb Porto Alegre (Ser9Cys) [10]). Heterogeneity of functionally different alpha and beta globins in mice but not humans means that mouse globin gene variation can contribute to phenotypic and experimental variation in ways that do not occur in humans.…”

Section: Introductionmentioning

confidence: 99%

Analysis of murine S-glutathionyl hemoglobins and beta globin haplotype by dynamic capillary isoelectric focusing

Hempe

McGehee

Stoyanov

2009

Journal of Chromatography B

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“…Turtle, frog and some mouse haemoglobins polymerize by the formation of intermolecular disulphide bridges (Riggs, Sullivan and Agee, 1964;Riggs, 1965). Three polymeric, natural human haemoglobin mutants also have been described: haernoglobin P6rto Alegre (j3(A6) serine --cysteine) (Tondo et al, 1974), haemoglobin Mississippi (P(CD3) serine -cysteine) (Adams et al, 1987), and haemoglobin Ta-Li (P(EF7) glycine -cysteine) (Blackwell, Liu and Wang, 1971). Each of these human mutants has a residue on the surface of the 03-subunit that is replaced by a cysteine residue capable of forming intermolecular disulphide bonds.…”

Section: Haemoglobin Design By Recombinant Dna Engineering Natural Mumentioning

confidence: 99%

Biotechnology and genetic engineering reviews, Volume 2

1985

Food and Chemical Toxicology

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Blood •tdOstitutes 4015Early studies with haemoglobin-based blood substitutesCell-free haemoglobin solutions were first administered to humans at the end of the nineteenth century. Serious side-effects were not noted with small amounts of haemoglobin, but the solutions were unstable and the experimental results were difficult to interpret (Von Stark, 1898: Sellards andMinot. 1916). In the 1930s, Amberson performed complete exchange transfusions in cats with haemoglobin solutions that were tolerated well (Mulder et af.. 1934: Amberson, 1937. Those studies led this group to conduct clinical trials in humans that ended with mixed results (Amberson, Jennings and Rhode. 1949). Some anaemic patients experienced erythropoietic stimulation, but one patient in shock with post-partum haemorrhage developed sepsis and oliguria and died with renal failure. Amberson pointed out that renal failure was not unexpected in this patient, even without administration of haemoglobin. Nevertheless, this result emphasized the possible dangers of complications with haemoglobin solutions. Deleterious side-effects, including oliguria. hypertension, and slowed heart beat continued to be observed during Carly human studies. It was clear that new methods for the evaluation of haemoglobin structure, function, stability, and purity were required before further progress in haemoglobin-based blood substitutes could be achieved (for a review, see Winslow, 1992).the haemoglobin molecule: structure, function and stability TFIE HAEMOGLOBIN MOLECULEHuman haemoglobin is a globular protein of 64 kDa consisting of two similar pairs of c,-and ýi-suhunits related symmetrically on a dyad axis. Each subunit has associated with it a ferroprotoporphyrin IX (haem) prosthetic group. The unlike subunits have a strong interaction with one another within an ac4 dimer, and two ac3 dimers combine in a weaker interaction to form the symmetrical CY 2 0 2 tetramer (Figure 1). The subunits are primarily helical in tertiary structure: the turns between helices are the only non-helical segments in the molecule. The a-subunits contain 141 amino acids arranged in seven helices: A, B. C. E, F, G and I1. The fi-subunits contain 146 amino acids and have an extra D helix. The functional importance of the difference in helical content of the a-and {f-subunits is not completely understood, but ji-tetramers are non-cooperative and unstable. Recently it has been shown by genetic engineering that forcing a D helix into the a-subunits or deleting the D helix from the [i-subunits has little effect on 02 binding (Komiyama et al., 1991).The interaction between haem and globin is of particular concern in the design of a haemoglobin-based blood substitute. Apoglobin is insoluble in physiological media, and free haem is toxic. Haem is positioned between the E and F helices by hydrophobic and hydrophilic interactions with globin residues (Perutz et al., 1968). The E helix forms a distal pocket over the haem, where ligand binding occurs to the sixth-coordination site of the haem 406 KIM D. VA...

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Functional properties of hemoglobin pôrto alegre (α2Aβ29 Ser→Cys) and the reactivity of its extra cysteinyl residue

Cited by 46 publications

References 13 publications

A polymerising Root‐effect fish hemoglobin with high subunit heterogeneity

A polymerising Root‐effect fish hemoglobin with high subunit heterogeneity

Analysis of murine S-glutathionyl hemoglobins and beta globin haplotype by dynamic capillary isoelectric focusing

Biotechnology and genetic engineering reviews, Volume 2

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