Joseph Horwitz, PhD, Director
Phone: (310) 206-5744
Fax: (310) 794-2144
Email: [email protected]
Stein Eye Institute
100 Stein Plaza, Room B-168
Los Angeles, CA 90095
Biophysics of the Crystalline Lens
Ophthalmic Biophysical Chemistry
Dr. Horwitz is conducting research on the biochemical and biophysical properties of the eye lens proteins. His current goals are to elucidate the function and structure of the small heat-shock protein alpha-crystallin. The various properties of this small, heat-shock protein, which is also a molecular chaperone, are being probed by a variety of physico-chemical techniques including site-directed spin labeling and cryo-electron microscopy. Also under study are the effects of aging and cataract on the chaperone function of alpha-crystallin and the interaction of alpha-crystallin with other lens proteins in an environment that mimics the high concentration of lens protein in situ. The protein concentration in the eye lens reaches levels of 500mg/ml.
Horwitz J. Alpha-crystallin can act as a molecular chaperone. Proc Natl Acad Sci 1992;89:10449-53.
Bova MP, Ding L, Horwitz J, Fung B. Subunit exchange of aA-crystallin. J Biol Chem 1997;272:29511-17.
Haley DA, Horwitz J, Stewart PL. The small heat-shock protein, aB-crystallin has a variable quarternary structure. J Mol Biol 1998;277:27-35.
Bova MP, Orna Y, Huang QL, Ding L, Haley DA, Stewart PL, Horwitz J. Mutation R120G in a aB-Crystallin, which is linked to a desmin-related myopathy, results in an irregular structure and defective chaperone-like function. Proc Natl Acad Sci 1999;96:6137-42.
Horwitz J. The function of alpha-crystallin in vision. Semin Cell Dev Biol 2000;11:53-60.
National Eye Institute: Alpha-Crystallin & Cataractogenesis, 8/1/04-7/31/10
Post Doctoral Fellowship