Technical Data
Crystallin, alpha B, phosphorylated (Ser45)
Aalpha-crystallins are composed of alphaA (~19kD) and alphaB (~19.2kD) subunits, are major water-soluble proteins accounting for almost 50% of total protein in the mammalian transparent eye lens and they are also found in a variety of other tissues (1). Alpha-crystallins are also referred to as small heat shock proteins, since they are induced by increased temperature in a variety of organisms. (2) The alpha-crystallins have sequence homology as well as structural and functional similarities with the small Hspís such as Hsp25/27 (3). Most alpha•crystallins have four common structural and functional features: (i) molecular weight between 12 and 43kDa; (ii) the formation of large oligomeric complexes composed of alphaA-crystallin, alphaB-crystallin and Hsp25/27; (iii) the moderately conserved alpha crystallin domain in the central region of the protein; and (iv) molecular chaperone activity (2,4). The alpha crystallin domain comprises approximately 90 residues, is bounded by variable N-terminal and C-terminal extensions and is involved in oligomer assembly. Oligomers can reach 800kDa or more and are dynamic, exhibiting subunit exchanges and organizational plasticity, possibly leading to functional diversity. Phosphorylation of serine residues occurs during development and in response to stress, and usually decreases oligomer size (4). Chaperone activity requires, and is modulated by, oligomerization and is limited to binding unfolded intermediates to prevent irreversible aggregation (2,4). Although productive release and refolding of denatured proteins requires close cooperation with other chaperones. Other proposed functions include a role in membrane stabilization (2) and modulation of intermediate filament organization during physiological stress and neurodegenerative disease (5). Alpha B Crystallin is phosphorylated on serine 45 by ERK1/2 and serine 59 by MAPKAPK-2 (6,7). When mono-phosphoylated alphaB-crystallin is isolated it contains only alphaB-crystallin phosphorylated at serine 19 (8).

Western Blot (Colorimetric): 1ug/mL
Immunoprecipitation: 12.5ug/mL
Optimal dilutions to be determined by researcher.
50ug-20°CBlue IceRatRabbit
Human synthetic peptide corresponding to amino acids 44-54 and containing phosphorylated serine 45. This peptide is identical among mouse, rat and bovine.
Supplied as a liquid in sodium phosphate buffer, pH 7.0, 3% BSA.
This antibody detects an ~22kD protein, corresponding to the apparent molecular mass of phosphorylated alphaB-crystallin on SDS-PAGE immunoblots, in samples human, mouse, rat, bovine, chicken, canine, guinea pig, hamster, monkey, porcine, rabbit, sheep and Xenopus. There is no reactivity with non-phosphorylated alphaB-crystallin.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
1. Augusteyn, R. C., Parkhill, E. M., and Stevens, A. (1992) Exp. Eye Res. 54: 219-228.
2. Narberhaus, F. (2002) Microbiol Mol Biol Rev 66(1): 64-93.
3. Merck, K. B., Groenen, P. J., Vooter, C. E., de Haard-Hoelman, W. A., Horwitz, J.,
Bloemendal, H. and de Jong, W. W. (1993) J. Biol. Chem. 268: 1046-1052.
4. MacRae, T.H. (2000) Cell Mol Life Sci 57(6): 899-913.
5. Head, M.W., Goldman, J.E. (2000) Neuropathol Appl Neurobiol 26(4): 304-312.
6. Armstrong, S.C., Shivell, C.L., Ganote, C.E., (2000) J Mol Cell Cardiol. 32(7):1301-
7. Ito H, Iida K, Kamei K, Iwamoto I, Inaguma Y, Kato K.. (1999) FEBS Lett. 446(2-3):
8. Kamei, A., Hamaguchi, T., Matsuura, N., Masuda, K. (2001) Biol Pharm Bull. 24(1): 96-