Characterization of IXINITY® (Trenonacog Alfa), a Recombinant Factor IX with Primary Sequence Corresponding to the Threonine-148 Polymorph

Figure 3

Circular dichroism spectroscopy was carried out in 25 mM MOPS, 150 mM NaClO₄, 5 mM CaCl₂, and pH 7.5 at approximately 1.0 mg mL⁻¹ factor IX. CD measurements were carried out with a 1 cm cell for near UV measurements and a 0.02 cm cell for far UV measurements. Five accumulations were obtained per spectrum. The spectrum of the buffer blank was subtracted from the sample spectra; then the observed ellipticities were converted to mean residue ellipticities using the protein concentration, the mean residue weight (112.2 Da), and the path length of the cell. Near UV spectra are shown in the upper panel. Far UV spectra are shown in the lower panel. The spectra from six trenonacog alfa lots are shown on each plot.

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