Structure and dynamics of Antarctic fish neuroglobin assessed by computer simulations

BORON, I.; RUSSO, R.; BOECHI, L.; CHENG, C.; DI PRISCO, G.G.; ESTRIN, D.A.; VERDE, C..; NADRA, A.D.

IUBMB LIFE

JOHN WILEY & SONS INC

Año: 2011 vol. 66 p. 206 - 213

1521-6543

Neuroglobin (Ngb) is a heme protein, highly conserved alongevolution, predominantly found in the nervous system. It is up-regulated by hypoxia and ischemia and may have a neuropro-tective role under hypoxic stress. Although many other roleshave been proposed, the physiological function is still unclear.Antarctic icefishes lack hemoglobin and some species also lackmyoglobin, but all have Ngb and thus may help the elucidationof Ngb function. We present the first theoretically derivedstructure of fish Ngb and describe its behavior using moleculardynamics simulations. Specifically, we sequenced and analyzedNgbs from a colorless-blooded Antarctic icefish species Chaeno-cephalus aceratus and a related red-blooded species (Dissosti-chus mawsoni). Both fish Ngbs are 6-coordinated but have somepeculiarities that differentiate them from mammalian counter-parts: they have extensions in the N and C termini that caninteract with the EF loop, and a gap in the alignment thatchanges the CD-region structure/dynamics that has been foundto play a key role in human neuroglobin. Our results suggestthat a single mutation between both fish Ngbs is responsible forsignificant difference in the behavior of the proteins. The func-tional role of these characteristics is discussed.