Fig. 2: Chitin-binding protein purification and identification of the binding affinity to chitin.

a The principle of detection C. albicans is based on the interaction of chitin and CBP. b Schematic flow diagram of the protein purification and affinity validation. c SDS-PAGE (12.5%) showing the induced expression profile and purification stages of chitin-binding protein. Marker: molecular mass marker; cell lysate: induced cell lysed by sonication; supernatant: the induced cell lysate was centrifuged at 13,000×g for 30 min and the supernatant was collected; and flow through: except that the target proteins with his-tag will bind to the Ni²⁺-NTA column, other substances, and miscellaneous proteins will directly flow through the column. Wash1-Wash3: washing the column with 50 mL of washing buffer containing 50 mmol/L of imidazole, 65 mmol/L of imidazole, and 80 mmol/L of imidazole, respectively. Elution: elute the target protein from the Ni²⁺-NTA column. d The seven purified soluble CBP. e Model of chitin-binding with the affinity protein. f, g ITC analysis to measure the binding affinity of chitin-binding to CBP (PfCBP-A and PfCBP-B). For c, d, each experiment was repeated three times, with one representative result shown. Source data are provided as a Source Data file.