ka is the association rate constant, p value is the correlation coefficient of the linear regression through the kon values, intercept is the kd value obtained from kon plots , kd is the dissociation rate constant obtained in the dissociation experiments in the presence of competing heparin, and Kd is the affinity calculated from the ratio of kd/ka. The standard errors (SE) were calculated from five independent association datasets and six independent dissociation datasets and combined for the calculation of Kd.