The electrochemical behaviour of Abelson protein-tyrosine kinase 1 (ABL1) and its interaction with synthetic substrate abltide EAIYAAPFAKKK, ATP, and inhibitors genistein, imatinib mesylate and danusertib were studied by differential pulse voltammetry using a glassy carbon electrode. In neutral electrolytes one oxidation peak due to histidine residues was observed. In acid and basic media the enzyme undergoes conformational modifications which lead to exposure of more electroactive amino acid to the electrode surface facilitating their oxidation. The interaction of ABL1 with the synthetic substrate involves the coiling of abltide-around the enzyme which suppresses the oxidation of abltide tyrosine residue and leads the exposure of ABL1 electroactive amino acids to the electrode surface and occurrence of new electrochemical signals. The binding of ATP and ATP-competitive synthetic inhibitors irnatinib mesylate, and danusertib results in stable complexes that maintains the symmetry of the enzyme but the electroactive centres of the compounds are hidden inside the binding site, preventing their oxidation. The natural inhibitor genistein is encountered on the outer surface of the enzyme and the electroactive centres are available for oxidation. (C) 2015 Elsevier B.V. All rights reserved.