title: Biochemical characterization of hemoglobins from Caspian Sea sturgeons (Acipenser persicus and Acipenser stellatus).
abstract: Hemoglobin (Hb) variability is a commonly used index of phylogenetic differentiation and molecular adaptation in fish enabling them to adapt to different ecological conditions. In this study, the characteristics of Hbs from two Sturgeon species of the Southern Caspian Sea Basin were investigated. After extraction and separation of hemoglobin from whole blood, the polyacrylamide gel electrophoresis (SDS-PAGE), cellulose acetate electrophoresis, and isoelectric focusing (IEF) were used to confirm Hb variabilities in these fishes. We showed that although both species have variable Hbs with different isoelectric points, their dominant Hbs can be identified. Ion exchange on CM-cellulose chromatography was used for purification of the dominant Hbs from these fishes. The accuracy of the methods was confirmed by IEF and SDS-PAGE. Spectral studies using fluorescence spectrophotometery indicated that although the Hbs from these fishes had similar properties they exhibited clear differences with human Hb. A comparative study of Hbs alpha-helix secondary substructures was performed by circular dichroism spectropolarimetry (CD) analysis. UV-vis spectrophotometery was also utilized to measure oxygen affinity of Hbs by sodium dithionite. Oxygen affinities of these Hbs were compared using Hb-oxygen dissociation curves. Together, these results demonstrate a significant relationship between oxygen affinity of fish hemoglobins and environmental partial pressure of oxygen.
authors.affiliation: Department of Marine Biology, Faculty of Marine Science and Technology, Science and Research Branch, Islamic Azad University (IAU), Tehran, Iran.
authors.forename: Shohreh
authors.initials: S
authors.lastname: Ariaeenejad
authors.forename: Mehran
authors.initials: M
authors.lastname: Habibi-Rezaei
authors.forename: Shahla
authors.initials: S
authors.lastname: Jamili
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Fatemi
authors.forename: Najmeh
authors.initials: N
authors.lastname: Poursasan
authors.forename: Faizan
authors.initials: F
authors.lastname: Ahmad
authors.forename: Nader
authors.initials: N
authors.lastname: Sheibani
authors.forename: Kaveh
authors.initials: K
authors.lastname: Kavousi
authors.forename: Ali A
authors.initials: AA
authors.lastname: Moosavi-Movahedi
mesh_terms: D000818:Animals; D002152:Calorimetry, Differential Scanning; D002942:Circular Dichroism; D004588:Electrophoresis, Cellulose Acetate; D004591:Electrophoresis, Polyacrylamide Gel; D005399:Fishes / Q000097:blood*; D006454:Hemoglobins / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D006801:Humans; D007525:Isoelectric Focusing; D009792:Oceans and Seas; D010100:Oxygen / Q000737:chemistry; D017433:Protein Structure, Secondary; D013045:Species Specificity
chemical_list: D006454:Hemoglobins; D010100:Oxygen