A novel protease may explain widely differing models for the structure of Artemia salina haemoglobin

Evidence that a protease is responsible for the proposal of differing models for the structure of the haemoglobin of the brine shrimp Artemia salina is presented. The protease, a minor contaminant in highly purified haemoglobin preparations, is activated by SDS of the SDS-polyacrylamide gel system and readily degrades the haemoglobin subunit. Removal of the protease by chromatography on Con A-Sepharose 4B has shown the haemoglobin ($\text{M}{}_{\mathrm{<mtext>r</mtext>}}\text{260 000}$) to comprise two subunits of $\text{M}{}_{\mathrm{<mtext>r</mtext>}}\text{130 000}$.