Physicochemical characterization of high-molecular-weight alpha-crystallin subpopulations from the calf lens nucleus.
Calf lens nuclear alpha-crystallin was separated into five molecular weight subpopulations by exclusion chromatography on Bio-Gel A-5m. These subpopulations were compared by amino acid analysis, ultraviolet absorption analysis, fluorescence, far- and near-ultraviolet circular dichroism, isoelectric focusing, SDS-polyacrylamide gel electrophoresis and sedimentation velocity analysis. Although only minor differences were detectable in most physicochemical properties, progressive changes were found in the near-ultraviolet circular dichroism spectra and in pellet hardness after centrifugation. Minute amounts of beta-crystallin polypeptides and a 43 kDa component were present in all five subpopulations. In addition, the highest molecular weight aggregates contain some gamma-crystallin polypeptides. A slow re-equilibration of separated subpopulations towards the initial distribution was observed by rechromatography.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D002467:Cell Nucleus / Q000032:analysis*; D002942:Circular Dichroism; D003459:Crystallins / Q000302:isolation & purification*; D007908:Lens, Crystalline / Q000032:analysis*; D008970:Molecular Weight; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
D000596:Amino Acids; D003459:Crystallins