The Hemoglobins of Fishes Living at Polar Latitudes - Current Knowledge on Structural Adaptations in a Changing Environment(742 views) Verde C, Vergara A, Mazzarella L, Di Prisco G
Keywords: Evolution, Hemoglobin, Polar Fish, Root Effect, X-Ray Structure, Hemoglobin Derivative, Oxygen, Antarctica, Arctic Climate, Biodiversity, Bohr Effect, Environmental Factor, Evolutionary Adaptation, Hemoglobin Determination, Latitude, Metabolism, Molecular Evolution, Morphological Adaptation, Nonhuman, Oceanography, Oxidation Reduction Reaction, Oxygen Affinity, Oxygen Transport, Phylogeny, Polar Ice Cap, Protein Function, Protein Quaternary Structure, Protein Structure, Review, Species Habitat, Teleost, Temperature Acclimatization, Temperature Sensitivity, X Ray Crystallography, Physiological, Animals, Arctic Regions, Cold Climate, Fish Proteins, Acanthomorpha, Notothenioidei, Pisces,
Affiliations: *** IBB - CNR ***
Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131 Naples, Italy
Department of Chemistry, University of Naples Federico II, Complesso Monte S. Angelo, Via Cinthia, I-80126 Naples, Italy
Institute of Biostructures and Bioimages, CNR, Via Mezzocannone 16, I-80134 Naples, Italy
References: Not available.
The Hemoglobins of Fishes Living at Polar Latitudes - Current Knowledge on Structural Adaptations in a Changing Environment
Fishes thriving in polar habitats offer many opportunities for comparative approaches to understanding protein adaptations to temperature. Notothenioidei, the dominant suborder in the Antarctic Ocean, have evolved reduction of hemoglobin concentration and multiplicity, perhaps as a consequence of temperature stability and other environmental parameters. In the icefish family, the blood pigment is absent. In contrast, similar to other acanthomorph teleosts, Arctic fish, thriving in a more complex oceanographic system, have maintained higher hemoglobin multiplicity and a highly diversified globin system in response to environmental variability and/or variations in metabolic demands. This review summarises the current knowledge on the structure, function and phylogeny of hemoglobins of fish living in polar habitats. On the basis of crystallographic analysis, a novel guideline to the interpretation of the Root effect in terms of a three-state model is suggested, implying the accessibility of an R/T intermediate quaternary structure, frequently observed in Antarctic fish hemoglobins. The occurrence of bis-histidyl and penta-coordinate states in ferric forms of polar fish hemoglobins suggests additional redox properties.
The Hemoglobins of Fishes Living at Polar Latitudes - Current Knowledge on Structural Adaptations in a Changing Environment