Disease relevance of Scapharca

• Influence of long-term hypoxia on the energy metabolism of the haemoglobin-containing bivalve Scapharca inaequivalvis: critical O2 levels for metabolic depression [1].

High impact information on Scapharca

• Increased osmotic pressure, which lowers the oxygen affinity in human hemoglobin, raises the oxygen affinity of Scapharca hemoglobin regardless of whether the solute is glycerol, glucose, or sucrose [2].
• These observations suggest that Scapharca hemoglobin has a unique heme structure that undergoes substantial redox-dependent rearrangements that stabilize the Fe-proximal histidine bond in the functional deoxy form of the protein but not in the ferric form [3].
• Hydroxide rather than histidine is coordinated to the heme in five-coordinate ferric Scapharca inaequivalvis hemoglobin [3].
• Residue Phe97, which is thought to play a central role in the cooperative functioning of Scapharca dimeric hemoglobin, has been mutated to leucine to test its proposed role in mediating cooperative oxygen binding [4].
• The quaternary structure of the Hb-D homodimer is compared with those from two other invertebrate hemoglobins from Scapharca inaequivalvis and Urechis caupo, which also have subunit-subunit interactions that involve the E and E' helices [5].

Biological context of Scapharca

• Unusual affinity of cyanide for ferrous and ferric Scapharca inaequivalvis homodimeric hemoglobin. Equilibria and kinetics of the reaction [6].
• Globin genes of the bivalve mollusk Scapharca inaequivalvis have the two intron/three exon organization typical of vertebrate and many invertebrate globins, with introns in highly conserved positions [7].

Associations of Scapharca with chemical compounds

• High-resolution crystal structures of the co-operative dimeric hemoglobin from the blood clam Scapharca inaequivalvis have been determined in the unliganded (deoxy) and carbon monoxide (CO) liganded states [8].
• The oxidation by ferricyanide of the dimeric (HbI) and tetrameric (HbII) hemoglobins from the bivalve mollusc Scapharca inaequivalvis has been studied in static and kinetic experiments [9].
• The in vivo expression and the functional and spectroscopic properties are reported for a mutant of the homodimeric haemoglobin of the mollusc Scapharca inaequivalvis (HbI), where residue threonine 72 (position 9 in the E helix) at the subunit interface has been substituted by isoleucine [10].
• Resonance Raman measurements carried out in parallel on ferrous and ferric Scapharca inaequivalvis dimeric hemoglobin cyanide derivatives allowed the identification of the electron density marker bands and heme core size marker bands in both derivatives in comparison with those obtained for the carbonmonoxy and deoxy adducts [11].
• The occurrence of N-methyl-D-aspartic acid in muscle extracts of the blood shell, Scapharca broughtonii [12].

Gene context of Scapharca

• Further, the pH-rate profile of N. mutabilis Mb, like that of the homodimeric hemoglobin (Hb) from Scapharca inaequivalvis (Coletta, M., Boffi, A., Ascenzi, P., Brunori, M. and Chiancone, E. (1990) J. Biol. Chem. 265, 4828-4830), can be described only by assuming a concerted proton-linked transition with n = 1.8 +/- 0 [13].
• The dimeric hemoglobin (HbI) from Scapharca inaequivalvis is highly homologous to the other known dimeric Acid hemoglobins [14].
• Three acetylcholinesterase (AChE) forms were detected and recovered from foot or gill tissues of the benthonic bivalve mollusk Scapharca inaequivalvis [15].
• Application of the method has shown the presence of NMDA in several tissues of S. broughtonii and Scapharca subcrenata [16].
• Effect of copper exposure on the antioxidant enzymes in bivalve mollusc Scapharca inaequivalvis [17].

Analytical, diagnostic and therapeutic context of Scapharca

• Stereochemistry of the Fe(II)- and Fe(III)-cyanide complexes of the homodimeric Scapharca inaequivalvis hemoglobin. A resonance Raman and FTIR study [11].
• Accumulation of beta-alanopine was observed for the first time in the adductor muscle of blood shell, Scapharca broughtonii, during aerial exposure by application of the HPLC detection method [18].

References