INVESTIGADORES
ESTRIN Dario Ariel
artículos
Título:
Biophysical characterization of neuroglobin of the icefish, a natural knockout for hemoglobin and myoglobin. Comparison with human neuroglobin
Autor/es:
D. GIORDANO; I. BORON; S. ABBRUZZETTI; W. VAN LEUVEN; F.P. NICOLETTI; F. FORTI; S. BRUNO; C. CHENG; L. MOENS; G. DI PRISCO; A. NADRA; D.A. ESTRIN; G. SMULEVICH; S. DEWILDE; C. VIAPPIANI; C. VERDE
Revista:
PLOS ONE
Editorial:
PUBLIC LIBRARY SCIENCE
Referencias:
Lugar: San Francisco; Año: 2012 vol. 7 p. 1 - 10
ISSN:
1932-6203
Resumen:
The Antarctic icefish Chaenocephalus aceratus lacks the globins common to most vertebrates, hemoglobin and myoglobin,
but has retained neuroglobin in the brain. This conserved globin has been cloned, over-expressed and purified. To highlight
similarities and differences, the structural features of the neuroglobin of this colourless-blooded fish were compared with
those of the well characterised human neuroglobin as well as with the neuroglobin from the retina of the red blooded,
hemoglobin and myoglobin-containing, closely related Antarctic notothenioid Dissostichus mawsoni. A detailed structural
and functional analysis of the two Antarctic fish neuroglobins was carried out by UV-visible and Resonance Raman
spectroscopies, molecular dynamics simulations and laser-flash photolysis. Similar to the human protein, Antarctic fish
neuroglobins can reversibly bind oxygen and CO in the Fe2+ form, and show six-coordination by distal His in the absence of
exogenous ligands. A very large and structured internal cavity, with discrete docking sites, was identified in the modelled
three-dimensional structures of the Antarctic neuroglobins. Estimate of the free-energy barriers from laser-flash photolysis
and Implicit Ligand Sampling showed that the cavities are accessible from the solvent in both proteins. Comparison of
structural and functional properties suggests that the two Antarctic fish neuroglobins most likely preserved and possibly
improved the function recently proposed for human neuroglobin in ligand multichemistry. Despite subtle differences, the
adaptation of Antarctic fish neuroglobins does not seem to parallel the dramatic adaptation of the oxygen carrying globins,
hemoglobin and myoglobin, in the same organisms.