Characterization of new D-beta-aspartate-containing proteins in a lens-derived cell line.
Although proteins are generally composed of l-alpha-amino acids, biologically uncommon D-beta-aspartic acid (Asp)-containing proteins have been reported in various tissues from elderly individuals. Our previous study indicated that the N/N1003A cell line, derived from rabbit lens, includes D-beta-Asp-containing proteins of approximately 50 kDa by Western blot analysis of a 2D-gel using a polyclonal antibody that is highly specific for D-beta-Asp-containing proteins. In this study, we identified the D-beta-Asp-containing proteins by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and the Mascot online database searching algorithm. The results indicate that one of these 50 kDa proteins is an enolase showing homology with tau-crystallin. Other D-beta-Asp-containing proteins, which we have recently discovered include lamin A/C, cytoplasmic NADP+-dependent isocitrate dehydrogenase, fructose-bisphosphate aldolase A, aldose reductase, L-lactate dehydrogenase A or calponin H2, phosphoglycerate mutase 1, phosphatidylethanolamine-binding protein, alpha-B-crystallin, and peptidyl-prolyl cis-trans isomerase A (PPlase).
Takata
Takumi
T
Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan, Osaka 590-0494, Japan.
Shimo-Oka
Tadashi
T
Miki
Kunio
K
Fujii
Noriko
N
D000818:Animals; D002460:Cell Line; D003459:Crystallins / Q000737:chemistry* / Q000378:metabolism*; D026581:Isoaspartic Acid / Q000737:chemistry* / Q000378:metabolism*; D007908:Lens, Crystalline / Q000737:chemistry* / Q000378:metabolism*; D008970:Molecular Weight; D011817:Rabbits
D003459:Crystallins; D026581:Isoaspartic Acid