Cloning, expression and purification of Atlantic salmon (Salmo salar, L.) neuroglobin

Abstract

Abbreviations: Ngb: neuroglobin, sNgb: salmon neuroglobin, hNgb: human neuroglobin, CO: carbon monoxide, ROS: reactive oxygen species, MBP: maltose binding protein. AbstractNeuroglobin (Ngb) exists only in small amounts in salmon brain. In order to study the protein in more detail salmon neuroglobin (sNgb) was cloned, hetereologously expressed in E.coli and purified. The protein had red color and showed the characteristic peaks at 411 nm (metNgb), 415 nm (carboxyNgb) and 424 nm (deoxyNgb). Western analysis showed that sNgb reacted weakly against a rabbit anti human neuroglobin (hNgb) and strongly to a sNgb specific antibody. Our 3D-homology model of the sNgb indicated modifications adjacent to and in the O 2 /CO binding site. This may correlate to differences in substrate affinities for the sNgb compared to the hNgb. Also sNgb contained shorter helixes and longer interhelical loops typical for psycrophilic proteins.