The nerve hemoglobin of the bivalve mollusc Spisula solidissima : molecular cloning, ligand binding studies, and phylogenetic analysis
Kreiling, Jill A.
Reinisch, Carol L.
Vanfleteren, Jacques R.
Marden, Michael C.
Van Doorslaer, Sabine
MetadataShow full item record
Members of the hemoglobin (Hb) superfamily are present in nerve tissue of several vertebrate and invertebrate species. In vertebrates they display hexacoordinate heme iron atoms and are typically expressed at low levels (µM). Their function is still a matter of debate. In invertebrates they have a hexa- or pentacoordinate heme iron, are mostly expressed at high levels (mM), and have been suggested to have a myoglobin-like function. The native Hb of the surf clam, Spisula solidissima, composed of 162 amino acids, does not show specific deviations from the globin templates. UV-visible and resonance Raman spectroscopy demonstrate a hexacoordinate heme iron. Based on the sequence analogy, the histidine E7 is proposed as a sixth ligand. Kinetic and equilibrium measurements show a moderate oxygen affinity (P50 ~0.6 torr) and no cooperativity. The histidine binding affinity is 100-fold lower than in neuroglobin. Phylogenetic analysis demonstrates a clustering of the S. solidissima nerve Hb with mollusc Hbs and myoglobins, but not with the vertebrate neuroglobins. We conclude that invertebrate nerve Hbs expressed at high levels are, despite the hexacoordinate nature of their heme iron, not essentially different from other intracellular Hbs. They most likely fulfill a myoglobin-like function and enhance oxygen supply to the neurons
Author Posting. © American Society for Biochemistry and Molecular Biology, 2006. This article is posted here by permission of American Society for Biochemistry and Molecular Biology for personal use, not for redistribution. The definitive version was published in Journal of Biological Chemistry 281 (2006): 5364-5372, doi:10.1074/jbc.M509486200.
Showing items related by title, author, creator and subject.
Molecular level characterization of methyl sugars in marine high molecular weight dissolved organic matter Panagiotopoulos, Christos; Repeta, Daniel J.; Mathieu, Laura; Rontani, Jean-Francois; Sempere, Richard (2013-03-04)Dissolved organic matter (DOM) is the largest active organic carbon reservoir in the ocean (662 Gt C), a major fraction (> 95%) of which remains chemically uncharacterized. The concentration and isolation of DOM from ...
The molecular biology of biogeochemistry : using molecular methods to link ocean chemistry with biological activity Unknown author (OCB Project Office, 2010-11)This workshop will convene molecular biologists and biogeochemists to determine what genomic and proteomic tools can be applied to important problems in the carbon, nitrogen and phosphorus cycles of the ocean through an ...
Characterization of methyl sugars, 3-deoxysugars and methyl deoxysugars in marine high molecular weight dissolved organic matter Panagiotopoulos, Christos; Repeta, Daniel J.; Johnson, Carl G. (2007-01-16)Nuclear magnetic resonance spectroscopy of marine high molecular weight dissolved organic matter (HMWDOM) in surface waters show that >50% of the carbon is a compositionally well-defined family of acylated-polysaccharides ...