Isolation and chemical characterization of some low molecular weight proteins of the bovine lens : Paper from the symposium “lens proteins and related subjects”, Ghent, Belgium, June 1967

Four low molecular weight proteins, designated as β2-, γ0-, γ1- and γ2-crystallin, have been isolated from the cortex of bovine lenses by gel filtration on Sephadex G-75, followed by chromatography on DEAE-Sephadex. The isolated proteins were found to be homogeneous in starch gel and/or agar electrophoresis. Efforts to determine any amino terminal group in β2-crystallin with the use of 2, 4-dinitrofluorobenzene failed. The carboxyl-terminal group determinations of β2-crystallin yielded glutamic acid in submolar quantities. The amino acid composition of each of the four proteins was determined and the molecular weights were calculated from these findings. On the basis of the amino acid composition the isolated proteins could be divided into three groups, which differ widely in some amino acids. Some unique features of amino acid composition are discussed