Chaperone activity of small heat shock proteins underlies therapeutic efficacy in experimental autoimmune encephalomyelitis.

Abstract

To determine whether the therapeutic activity of αB crystallin, small heat shock protein B5 (HspB5), was shared with other human sHsps, a set of seven human family members, a mutant of HspB5 G120 known to exhibit reduced chaperone activity, and a mycobacterial sHsp were expressed and purified from bacteria. Each of the recombinant proteins was shown to be a functional chaperone, capable of inhibiting aggregation of denatured insulin with varying efficiency. When injected into mice at the peak of disease, they were all effective in reducing the paralysis in experimental autoimmune encephalomyelitis. Additional structure activity correlations between chaperone activity and therapeutic function were established when linear regions within HspB5 were examined. A single region, corresponding to residues 73-92 of HspB5, forms amyloid fibrils, exhibited chaperone activity, and was an effective therapeutic for encephalomyelitis. The linkage of the three activities was further established by demonstrating individual substitutions of critical hydrophobic amino acids in the peptide resulted in the loss of all of the functions.

• Authors: Michael P Kurnellas, Sara E Brownell, Leon Su, Andrey V Malkovskiy, Jayakumar Rajadas, Gregory Dolganov, Sidharth Chopra, Gary K Schoolnik, Raymond A Sobel, Jonathan Webster, Shalina S Ousman, Rachel A Becker, Lawrence Steinman, Jonathan B Rothbard
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 287 Issue 43 Pg. 36423-34 (Oct 19 2012) ISSN: 1083-351X [Electronic] United States
• PMID: 22955287 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• CRYAB protein, human
• alpha-Crystallin B Chain

Topics

• Amino Acid Substitution
• Animals
• Encephalomyelitis, Autoimmune, Experimental (drug therapy, genetics, metabolism, pathology)
• Female
• Humans
• Mice
• Mutation, Missense
• Paralysis (genetics, metabolism, pathology, prevention & control)
• alpha-Crystallin B Chain (genetics, pharmacology)