Mapping protein-protein interaction sites and protein dynamics using HDXMS: Does binding to CK stabilize the ankyrin repeat domain of ASB9?

摘要

The ankyrin repeat and SOCS box (ASB) family is composed of 18 proteins and belongs to the suppressor of cytokine signaling (SOCS) box protein superfamily. The ASB proteins function as the substrate-recognition subunits of ECS-type (ElonginBC-Cullin-SOCS-box) Cullin RING E3 ubiquitin ligase (CRL) complexes that specifically transfer ubiquitin to cellular proteins targeting them for degradation by the proteasome. ASB9 binds to creatine kinase (CK) isoforms and targets it for degradation. We hypothesize that parts of ASB9 ARD folds upon binding to CK. We have used hydrogen deuterium exchange mass spectrometry (HDXMS) to look at structural changes that occur in ASB9 upon binding to CK and compared it to free ASB9-ARD and full length ASB9.