Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10771382 | Biochemical and Biophysical Research Communications | 2005 | 7 Pages |
Abstract
In this study, we screened for protein disulfide isomerase (PDI)-binding proteins in bovine liver microsomes under strict salt concentrations, using affinity column chromatography. One main band observed using SDS-PAGE was identified as ERp57 (one of the PDI family proteins) by LC-MS/MS analysis. The KD value of PDI binding to ERp57 was calculated as 5.46Â ÃÂ 10â6Â M with the BIACORE system. The interactions between PDI and ERp57 occurred specifically at their a and b domains, respectively. Interestingly, low concentrations of ERp57 enhanced the chaperone activity of PDI, while high concentrations interfered with chaperone activity. On the other hand, ERp57 did not affect the isomerase activity of PDI. Additionally, following pre-incubation of ERp57 with calreticulin (CRT), decreased interactions were observed between ERp57 and PDI, and vice versa. Based on the data, we propose that once ERp57 binds to PDI or CRT, the resultant complex inhibits further interactions. Therefore, ERp57 selectively forms a protein-folding complex with PDI or CRT in ER.
Related Topics
Life Sciences
Biochemistry, Genetics and Molecular Biology
Biochemistry
Authors
Taiji Kimura, Keisuke Imaishi, Yasunari Hagiwara, Tomohisa Horibe, Toshiya Hayano, Nobuhiro Takahashi, Reiko Urade, Koichi Kato, Masakazu Kikuchi,