Figure 4.

Identification of human ankyrin repeat and suppressor of cytokine signalling (SOCS) box protein 9 (ASB9) binding proteins. (a) Cell lysates were prepared from human embryonic kidney 293 (HEK293) cells that were stably transfected with the indicated expression vectors; immunoprecipitates were then generated by using an antibody to Myc epitope, after which they were resolved by SDS-PAGE and stained with Coomassie brilliant blue G-250. (b) The protein bands coimmunoprecipitated with ASB9 were digested in gel with trypsin, and the samples were analysed by electrospray ionization-time of flight mass spectrometry/mass spectrometry (ESI-TOF MS/MS). MS/MS analyses of the mass peaks (arrow) obtained from the 45-kDa band reveal the peptide spectra of CKB and ubiquitous mitochondrial creatine kinase (uMtCK).