Lucina pectinata oxyhemoglobin (II-III) heterodimer pH susceptibility

Marchany-Rivera, Darya; Smith, Clyde A.; Rodriguez-Perez, Josiris D.; López‐Garriga, Juan

doi:10.1016/j.jinorgbio.2020.111055

Cited by 5 publications

(2 citation statements)

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“…In the dark cytoplasmic patches [ 5 ] of L pectinata , HbIII is in the presence of HbII, which self‐associate to form a heterodimer. This heterodimer was previously suggested to be the active oxygen reactive protein [ 4,29 ] and forms a nonfunctional tetramer as a function of concentration. [ 4 ] Furthermore, protein expression analysis using L pectinata 's hemoglobin mRNA, compared to the18S rRNA of the clam, showed HbI, HbII, and HbIII are highly expressed in ctenidia.…”

Section: Resultsmentioning

confidence: 99%

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SAXS structure of homodimeric oxyHemoglobin III from bivalve Lucina pectinata

et al. 2021

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Hemoglobin III (HbIII) is one of the two oxygen reactive hemoproteins present in the bivalve, Lucina pectinata. The clam inhabits a sulfur‐rich environment and HbIII is the only hemoprotein present in the system which does not yet have a structure described elsewhere. It is known that HbIII exists as a heterodimer with hemoglobin II (HbII) to generate the stable Oxy(HbII‐HbIII) complex but it remains unknown if HbIII can form a homodimeric species. Here, a new chromatographic methodology to separate OxyHbIII from the HbII‐HbIII dimer has been developed, employing a fast performance liquid chromatography and ionic exchange chromatography column. The nature of OxyHbIII in solution at concentrations from 1.6 mg/mL to 20.4 mg/mL was studied using small angle X‐ray scattering (SAXS). The results show that at all concentrations, the Oxy(HbIII‐HbIII) dimer dominates in solution. However, as the concentration increases to nonphysiological values, 20.4 mg/mL, HbIII forms a 30% tetrameric fraction. Thus, there is a direct relationship between the Oxy(HbIII‐HbIII) oligomeric form and hemoglobin concentration. We suggest it is likely that the OxyHbIII dimer contributes to active oxygen transport in tissues of L pectinata, where the Oxy(HbII‐HbIII) complex is not present.

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Section: Resultsmentioning

confidence: 99%

“…Another potential factor regulating the protein oligomerization is the CRP present in the clam. [ 3,4,29,30 ] However, this is an open question, and additional studies are necessary to reveal the role of the CRP in this pathway.…”

Section: Resultsmentioning

confidence: 99%