Table 1.

Thrombin binds polyP with high affinity

	Kd (nM) at 50 mM NaCl*	Kd (nM) at 150 mM NaCl*
WT thrombin	4.9 ± 0.5	5.4 ± 0.4
K248A {236} mutant	12.2 ± 1.6	NB†

^*Binding of polyP₇₅ to immobilized biotin-thrombin (WT and mutant) was quantified in surface plasmon resonance studies at 50 mM and 150 mM NaCl. K_d values in this table are given in terms of polyP polymer concentration (mean ± S.D.; n = 3).

^†NB, negligible binding.