Fig. 7.

Heme transfer of LmCld to apomyoglobin. The transfer of the prosthetic group of 1 μM holo-LmCld to 5, 7.5, 10, and 15 μM apo-Mb was observed by the increase in absorbance at 409 nm. (A) Time traces when 1 μM holo-LmCld was mixed with 5–15 μM apo-LmCld in 100 mM phosphate buffer, pH 7.0. Double exponential fits are depicted in gray. The inset shows the linear dependence of k_obs1 values from the apo-Mb concentration. The apparent association rate constant, k_on, was calculated from the slope and the apparent dissociation rate constant, k_off, from the intercept. (B) UV–vis spectra of undiluted holo-LmCld (black) prior to the measurement and one representative spectrum of the mixture of LmCld and Mb after 1200 s (red). Holo-Mb is depicted as gray dashed line for comparison. The inset depicts holo-Mb and apo-Mb after heme extraction. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)