The apparent molecular size of native alpha-crystallin B in non-lenticular tissues.
The apparent molecular size of the native alpha-crystallin B in cytosol preparations from rat heart, brain and retina was determined by gel permeation chromatography, detecting the protein by immunochemical assay (ELISA), using an alpha-crystallin specific antiserum. Native alpha-crystallin from cytosol preparations of rat lens cortex was used as a reference. alpha-Crystallin B present in all three cytosol preparations from non-lenticular tissues eluted in a single symmetrical peak, with the same elution volume as alpha-crystallin from lens cortex cytosol preparations, corresponding to an apparent average molecular size of 0.8 x 10(6) Da. No other species could be detected. The results indicate that the alpha-crystallin aggregates characterized by an apparent average molecular mass of 0.8 x 10(6) Da, and considered to be the native, physiological form of the protein in the lens, are indeed not specific to lens tissue. Furthermore, the size of these alpha-crystallin aggregates is independent of their polypeptide composition. Aggregates found in the lens, composed of alpha A and alpha B polypeptides and their respective phosphorylated forms alpha Ap and alpha Bp, are similar in size to those found in heart, brain and retina, containing the alpha B but not the alpha A polypeptide.
Chiesa
R
R
Department of Ophthalmology, College of Physicians & Surgeons, Columbia University, New York, NY 10032.
McDermott
M J
MJ
Mann
E
E
Spector
A
A
D000818:Animals; D001923:Brain Chemistry; D002850:Chromatography, Gel; D003459:Crystallins / Q000032:analysis*; D008970:Molecular Weight; D009206:Myocardium / Q000032:analysis; D011485:Protein Binding; D051381:Rats; D011919:Rats, Inbred Strains; D012160:Retina / Q000032:analysis
D003459:Crystallins