alpha-Crystallin quaternary structure: molecular basis for its chaperone activity.
alpha-Crystallin, the major protein in all vertebrate lenses, functions as a chaperone. In the present analysis, an 'open' micellar structure composed of alpha A subunits is used to simulate chaperoning of partially heat denatured soluble gamma-crystallin. The interaction is both electrostatic and hydrophobic and satisfies experimental evidence for a 1:1 alpha/gamma molar ratio, a doubling of molecular mass and a minimal increase in the dimensions of the complex [J. Biol. Chem. (1994) 269, 13601-13608; Invest. Opthalmol. Vis. Sci. (1995) 36, 311-21]. These data are also in accord with Farahbaksh et al. [Biochemistry (1995) 34, 509-16]; i.e. the bound gamma-crystallin monomers are not in a central cavity, but are separated by alpha A subunits.
Singh
K
K
UMD, Department of Ophthalmology, New Jersey Medical School, Newark, USA.
Groth-Vasselli
B
B
Kumosinski
T F
TF
Farnsworth
P N
PN
D000595:Amino Acid Sequence; D003459:Crystallins / Q000737:chemistry*; D018832:Molecular Chaperones / Q000737:chemistry*; D008969:Molecular Sequence Data; D011487:Protein Conformation
D003459:Crystallins; D018832:Molecular Chaperones