title: Further studies on low molecular weight crystallins: relationship between the bovine beta s, the human 24kD protein and the gamma-crystallins.
abstract: Three classes of monomeric crystallins separable by SDS gel electrophoresis or by gel filtration have been demonstrated in human lens. In previous studies we have concluded from physico-chemical and immunological data that all three polypeptides are related and should be classified as gamma-crystallins. The present paper presents further evidence supporting this conclusion, but also demonstrates that the 24,000 dalton (24kD) polypeptide corresponds to the beta s-crystallin. beta s-crystallin was purified by classical techniques from bovine lens and was shown to cross-react with a monoclonal antibody specific for the human 24kD polypeptide. This antibody exhibited no reactivity to other crystallin fractions from either bovine or human lenses. The identification of the 24kD polypeptide as beta s was further supported by analysis of the tertiary structures of the molecules by near UV-circular dichroism and by the finding of a blocked amino terminus on the 24kD polypeptide. Our finding that the human beta s (24kD polypeptide) should actually be classified as a gamma-crystallin is fully consistent with recently reported sequence data on bovine beta s-crystallin.
mesh_terms: D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D003459:Crystallins / Q000145:classification*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008970:Molecular Weight; D014466:Ultraviolet Rays
chemical_list: D003459:Crystallins