Alpha, beta, and gamma crystallins in the ocular lens of rabbits: preparation and partial characterization.

Abstract

Alpha, beta, and gamma crystallins from rabbit eye lens have been prepared by continuousflow paper electrophoresis and gel filtration. These methods yielded well-defined fractions in a highly reproducible manner with essentially quantitative recovery of material. The behavior of each of the crystallins in diethylaminoethyl cellulose has been examined. Sulfhydryl contents of 2.9, 6.1, and 26.0 moles per 10 5 Gm. of protein were found for alpha, beta, and gamma crystallin, respectively. These values were altered to 5.9 and 8.5 for alpha and beta crystallin in 8 M urea, but that for gamma crystallin tvas unchanged. Extinction coefficients, E^so, of 8.3, 21.5, and 17.6 were found for alpha, beta, and gamma crystallin, respectively. Sedimentation constants of 18.9 S and 2.5 S toere calculated for alpha and gamma crystalline, respectively. Glycine tvas found to be the N-terminal amino acid of gamma crystallin. The presence of free N-terminal amino acids for alpha and beta crystallins could not be demonstrated. For these parameters, the characteristics of the rabbit lens crystallins are similar to those of bovine origin.