Oxygen binding properties of haemocyanin from Levantina hierosolima

Er-El, Z.; Shaklai, Nurith; Daniel, Ezra

doi:10.1016/0022-2836(72)90502-5

Cited by 47 publications

(36 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2C). Our calculations indicate that O 2 binding in Hc is exothermic by Ϫ2.9 kcal mol Ϫ1 , which is in reasonable agreement with experiment (⌬H ϭ Ϫ11.5 to Ϫ6.0 kcal mol Ϫ1 and ⌬G ϭ Ϫ5.0 kcal mol Ϫ1 at 25°C) (37)(38)(39)(40)(41). Key structural features are consistent with experimental data, yielding the side-on -2 : 2 O 2 2Ϫ core structure with R(Cu-Cu) of 3.55 Å (experimental Ϸ3.6 Å).…”

supporting

confidence: 88%

Geometric and electronic structure differences between the type 3 copper sites of the multicopper oxidases and hemocyanin/tyrosinase

Yoon

Fujii

Solomon

2009

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

View full text Add to dashboard Cite

supporting

confidence: 88%

Geometric and electronic structure differences between the type 3 copper sites of the multicopper oxidases and hemocyanin/tyrosinase

Yoon

Fujii

Solomon

2009

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

View full text Add to dashboard Cite

“…Levantina hierosolima hemocyanin shows a somewhat similar effect of pH on the oxygen binding [18], and recently the same phenomenon was reported in the case of Limuluspolyphemus hemocyanin with respect to chloride ions [7]. For human hemoglobin a similar situation occurs, since Kr is significantly influenced both by pH and by 2,3-bisphosphoglycerate [19,20].…”

Section: Oxygen Binding Behaviour Of' Fl-hemocyaninmentioning

confidence: 51%

Dissociation and Oxygen‐Binding Behaviour of β‐Hemocyanin from Helox pomatia

Zolola

Kuiper

Vecchini

et al. 1978

European Journal of Biochemistry

View full text Add to dashboard Cite

The dissociation behaviour of Helix pomatia j-hemocyanin as influenced by pH, calcium-ion concentration and ionic strength, and the oxygen binding properties were investigated. The dissociation behaviour of j-hemocyanin and a-hemocyanin differs distinctly in a number of properties : (a) they show a different response to high salt concentration, (b) the stabilizing influence of calcium ions on the whole molecules of P-hemocyanin is smaller than that on a-hemocyanin, (c) half molecules of P-hemocyanin are stabilized to a large extent in the presence of calcium ions and (d) at low ionic strength no peak separation between one-tenth and one-twentieth molecules of /I-hemocyanin is observed in the ultracentrifuge, which indicates an equilibrium between the species.The oxygen binding behaviour of P-hemocyanin shows the typical features of proteins with a large number of binding sites. The Hill plot is characterized by a high value of the Hill coefficient (maxm nH = 7), coupled to a low value for the interaction free energy per site. The oxygen binding behaviour can basically be described by a modified two-state allosteric model with the variation, imposed by the experimental data, that Kr is pH-dependent (negative Bohr efTect), while K R is pHindependent. Regulation of the cooperativity by the allosteric effector H + is mainly due to changes in the allosteric equilibrium constant.In order to describe the cooperativity as a function of pH, the minimum number of interacting binding sites has to be varied, indicating that the size of the 'functional constellations' is variable. This finding may have important implications on the relationship between the so-called 'structural' and 'functional constellations'.

show abstract

“…228 One important difference between L. hierosolima and P. interruptus is the affinity of the monomer. In L. hierosolima , monomeric Hc has identical thermodynamic parameters to the R-state, 228 while the monomer in P. interruptus is that of the T-state 199 (the affinity of the monomer in H. pomatia is unknown). This difference would necessitate differential subunit interactions to induce cooperativity and could explain the different trends in the thermodynamic parameters.…”

Section: Copper Active Sites That Activate Dioxygenmentioning

confidence: 99%