Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0086543 (cataract)
 29,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We present a study of binary mixtures of eye lens crystallin proteins. A coarse-grained model of aqueous alpha- and gamma-crystallin mixtures based on molecular dynamics simulations and SANS experiments is proposed. Thermodynamic perturbation theory is implemented to obtain the stability boundaries, or spinodal surface, of the binary mixture in the full parameter space. The stability of these high-concentration crystallin mixtures was found to depend on the alpha-gamma attraction in a manner that is both extremely sensitive and nonmonotonic; stronger or weaker attraction resulted in a spectacularly enhanced instability. The relevance of these mechanisms as possible sources of the alteration of the spatial distribution of the lens proteins encountered in cataract disease is discussed.
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PMID:Colloidal characterization and thermodynamic stability of binary eye lens protein mixtures. 1919 67

Aggregation states of human alpha-crystallins are observed complementarily using small-angle X-ray and small-angle neutron scatterings (SAXS and SANS). Infant alpha-crystallin is almost a monodispersed system of the aggregates with gyration radius of ca. 60 A, which is a normal aggregate. On the other hand, the aged and cataract alpha-crystallins have not only the normal but also the larger aggregates. In the aged alpha-crystallin, the normal aggregate is a major component, but in the cataract alpha-crystallin the larger ones are dominant. Both alpha A- and alpha B-crystallins, which are subunits of alpha-crystallin, also form an aggregate with the size close to the normal aggregate. Under UV irradiation, only aggregates of alpha B-crystallin undergo further aggregation. Therefore, considering increase of ratio of alpha B-crystallin in the aggregate of alpha-crystallin as aging, the abnormal aggregation (formation of the huge aggregates) mainly results in the further aggregation of alpha B-crystallin caused by external stresses.
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PMID:SAXS and SANS observations of abnormal aggregation of human alpha-crystallin. 2056 57