The structural stability and chaperone activity of artemin, a ferritin homologue from diapause-destined Artemia embryos, depend on different cysteine residues.

ABSTRACT: Diapause-destined embryos of the crustacean, Artemia franciscana, accumulate large amounts of an oligomeric, heat-stable, molecular chaperone termed artemin, a cysteine-enriched ferritin homologue. In this study, cysteines 22, 61, 166, and 172 of artemin were substituted with alanines, respectively yielding ArtC22A, ArtC61A, ArtC166A, and ArtC172A. Wild-type and modified artemins were synthesized in transformed bacteria and purified. As measured by heat-induced denaturation of citrate synthase in vitro, each substitution reduced chaperone activity, with ArtC172A the least active. Protein modeling indicated that C172 is close to a region of surface hydrophobicity, also present in ferritin, suggesting that this site contributes to chaperone activity. Only slight differences in oligomer molec

SUBMITTER: Hu Y 

PROVIDER: S-EPMC3059798 | biostudies-literature | 2011 Mar

REPOSITORIES: biostudies-literature