i have a doubt in binding affinity prediction. My doubt is im getting positive value for affinity. The formula i used to calculate is kd=[l][p]/[lp], where l is ligand molar concentration and p is protein molar concentration and [lp] is complex molar concentration. I calculated molar concentration by keeping the molecular weight of ligand, protein and complex respectively. The value atlast i get is kd=6.69. If i take log for this im gettin in 0.83. But the affinity value should be in negative only right? Is this correct or not? Kindly anyone help to sort out this