Enhanced stability of alpha B-crystallin in the presence of small heat shock protein Hsp27.
Lens alpha-crystallin, alpha A- and alpha B-crystallin, and Hsp27 are members of the small heat shock protein family. Both alpha A- and alpha B-crystallin are expressed in the lens and serve as structural proteins and as chaperones, but alpha B-crystallin is also expressed in nonlenticular organs where Hsp27, rather than alpha A-crystallin, is expressed along with alpha B-crystallin. It is not known what additional function Hsp27 has besides as a heat shock protein, but it may serve, as alpha A-crystallin does in the lens, to stabilize alpha B-crystallin. In this study, we investigate aspects on conformation and thermal stability for the mixture of Hsp27 and alpha B-crystallin. Size exclusion chromatography, circular dichroism (CD), and light scattering measurements indicated that Hsp27 prevented alpha B-crystallin from heat-induced structural changes and high molecular weight (HMW) aggregation. The results indicate that Hsp27 indeed promotes stability of alpha B-crystallin.
Fu
Ling
L
Center for Ophthalmic Research, Brigham and Women's Hospital, and Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA.
Liang
Jack J-N
JJ
D000818:Animals; D002942:Circular Dichroism; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008970:Molecular Weight; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013696:Temperature; D038203:alpha-Crystallin B Chain / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D006360:Heat-Shock Proteins; D011994:Recombinant Proteins; D038203:alpha-Crystallin B Chain