title: The interaction of hemerythrin with sodium dodecyl sulfate and the release of iron from the product with desferrioxamine B.
abstract: The interactions with sodium dodecyl sulfate (SDS) of methemerythrin, the anionic derivatives and oxyhemerythrin from Phascolopsis gouldii have been examined at 25 degrees C, I = 0.5 M and pH 6.3 and 7.8. Absorbance changes in the 350-500 nm range were used to monitor the rates. The denaturation is slow (k = 10(-2)-10(-3) s-1) and only slightly dependent on SDS concentration. Perchlorate is a very effective inhibitor of the SDS reaction with methemerythrin, and it is concluded that rapid binding of SDS near to the cysteine-50 site is an essential to unfolding. Myohemerythrin (from Themiste zostericola) and the monomeric N-ethylmaleimide derivatives of methemerythrin from P. gouldii and T. zostericola, in contrast, react rapidly with SDS. The products from denaturing of all proteins appear similar, having reduced alpha-helix content, very small absorbance in the 350-500 nm region and loss of anion or oxygen binding capacity. They do, however, retain the two irons, which can readily be removed with desferrioxamine B.
mesh_terms: D000818:Animals; D000845:Annelida; D003676:Deferoxamine / Q000494:pharmacology*; D006422:Hemerythrin / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D007700:Kinetics; D008433:Mathematics; D008667:Metalloproteins / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate / Q000378:metabolism*
chemical_list: D006422:Hemerythrin; D008667:Metalloproteins; D012967:Sodium Dodecyl Sulfate; D007501:Iron; D003676:Deferoxamine