Expression, purification, and crystallization of recombinant human ABL1 kinase domain for x-ray crystallography-based structural studies

The Abelson1 (ABL1) is a member of the Abelson (ABL) non-receptor tyrosine kinase family and is central to the regulation of several cellular processes, such as proliferation, survival, and differentiation. ABL1 is composed of several functionally distinct and structurally specialized domains; including an N-terminal cap region, SH2 and SH3 domains, a bilobed kinase domain, and a C-terminal tail, each playing a role in both regulating kinase activity and participating in complex signaling cascades. Under normal cellular conditions, the ABL1 kinase is found in an inactive state and becomes activated according to cellular needs. The aberrant ABL1 activity is associated with cellular abnormalities and disease pathogenesis including Chronic Myeloid Leukemia (CML). CML is a blood cancer type that is characterized by the constitutively active BCR-ABL1 protein arising from the fusion of ABL1 with the Breakpoint Cluster Region (BCR) gene. The deletion of the regulatory sequences of ABL1 and the insertion of additional BCR fragments leads to the constitutive activation of the BCR-ABL1 protein and oncogenic effects. The central role of ABL1 in the progression of CML, makes it the main target for the treatment approaches. Tyrosine kinase inhibitors (TKIs) targeting ABL1 provide an effective strategy for CML treatment by blocking the oncogenic, constitutive activity arising from the BCR-ABL1 fusion. Despite the success of the TKIs in the management of CML, there is a need for new strategies and treatment approaches to improve the treatment efficiency and outcomes. The structural studies that focus on the enlightening structural features of the ABL1 kinase are crucial for the development of novel TKIs and therapeutic approaches for the effective management of CML. This study focuses on the expression, purification and crystallization of ABL1 kinase for its structural investigations that could contribute to the development of novel therapeutics and drug screening platforms.