PUBLICATION
Structural and kinetic characterization of myoglobins from eurythermal and stenothermal fish species
- Authors
- Madden, P.W., Babcock, M.J., Vayda, M.E., and Cashon, R.E.
- ID
- ZDB-PUB-040405-4
- Date
- 2004
- Source
- Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology 137(3): 341-350 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- Adaptation, Physiological*
- Amino Acid Sequence
- Animals
- Environment
- Fishes
- Kinetics
- Models, Molecular
- Myoglobin/chemistry*
- Myoglobin/metabolism
- Oxygen/metabolism
- Pliability
- Protein Conformation
- Sequence Alignment
- Temperature*
- PubMed
- 15050521 Full text @ Comp. Biochem. Physiol. B Biochem. Mol. Biol.
Citation
Madden, P.W., Babcock, M.J., Vayda, M.E., and Cashon, R.E. (2004) Structural and kinetic characterization of myoglobins from eurythermal and stenothermal fish species. Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology. 137(3):341-350.
Abstract
Teleost myoglobin (Mb) proteins from four fish species inhabiting different temperature environments were used to investigate the relationship between protein function and thermal stability. Mb was isolated from yellowfin tuna (homeothermal warm), mackerel (eurythermal warm), and the Antarctic teleost Notothenia coriiceps (stenothermal cold). Zebrafish (stenothermal tropical) myoglobin was expressed from cloned cDNA. These proteins differed in oxygen affinity, as measured by O(2) dissociation rates and P(50) values, and thermal stability as measured by autooxidation rates. Mackerel Mb had the highest P(50) value at 25 degrees C (3.7 mmHg), corresponding to the lowest O(2) affinity, followed by zebrafish (1.0 mmHg), yellowfin tuna (1.0 mmHg), and N. coriiceps (0.6 mmHg). Oxygen dissociation rates and Arrhenius plots were similar between all teleost species in this study, with the exception of mackerel myoglobin, which was two-fold faster at all temperatures tested. Myoglobin from the Antarctic teleost had the highest autooxidation rate (0.44 h(-1)), followed by mackerel (0.26 h(-1)), zebrafish (0.22 h(-1)), and yellowfin tuna (0.088 h(-1)). Primary structural analysis revealed residue differences distributed throughout the polypeptide sequences, making it difficult to identify, which, if any, residues contribute to structural flexibility. However, analysis of molecular dynamics trajectories indicates that Mb from the eurythermal mackerel is predicted to be the most flexible protein within the D loop and FG turn. At the same time, it has the lowest O(2) affinity and the highest O(2) dissociation rates when compared to myoglobins from teleosts that appear to be less flexible in our dynamics simulations.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping