NO binding to ferric Mb and hxHbs.

Plots of k_obs versus [NO] for Mb and each hxHb. Time courses giving rise to these values were measured at different [NO] ranging from 50 to 1700 µM (after mixing) and were fitted to a single exponential to extract the observed rate constants (k_obs). A linear fit of these data provides the observed ferric NO binding association rate constant (k_{obs, NO(Fe3+)}).