SAXS structure of homodimeric oxyHemoglobin III from bivalve Lucina pectinata.

Autor: Marchany-Rivera D; Chemistry Department and Industrial Biotechnology Program, University of Puerto Rico, Mayagüez, Puerto Rico., Estremera-Andújar RA; Natural Sciences Department, University of Puerto Rico, Aguadilla, Puerto Rico., Nieves-Marrero C; Natural Sciences Department, University of Puerto Rico, Aguadilla, Puerto Rico., Ruiz-Martínez CR; Natural Sciences Department, University of Puerto Rico, Aguadilla, Puerto Rico., Bauer W; Hauptman-Woodward Medical Research Institute, Buffalo, New York, USA., López-Garriga J; Chemistry Department and Industrial Biotechnology Program, University of Puerto Rico, Mayagüez, Puerto Rico.
Jazyk: angličtina
Zdroj: Biopolymers [Biopolymers] 2021 Jun; Vol. 112 (6), pp. e23427. Date of Electronic Publication: 2021 Apr 01.
DOI: 10.1002/bip.23427
Abstrakt: 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.
(© 2021 Wiley Periodicals LLC.)
Databáze: MEDLINE
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