Table 1.

Ligand-binding affinity of QTY code designed chemokine receptor (E. coli)

	CCL5* Kd, nM	CXCL11 Kd, nM	CXCL12* Kd, nM	CXCL13 Kd, nM	CCL27 Kd, nM	CCL28 Kd, nM	gp41-120 Kd, nM
CXCR4 native			∼5				∼200†
CXCR4QTY buffer			17.3 ± 4.2				7.0 ± 1.9
CXCR4QTY serum			31.4 ± 12.2				12.7 ± 2.6
CXCR5 native				∼50.5
CXCR5QTY buffer				5.7 ± 2.2
CXCR5QTY serum				10.1 ± 2.6
CXCR7 native		∼8	∼4.5				N/A
CXCR7QTY buffer		6.4 ± 1.2	6.7 ± 2.2				34.3 ± 6.1
CXCR7QTY serum		51.5 ± 11.8	16.9 ± 3.4				50.0 ± 11.1
CCR5 native	∼4						∼10
CCR5QTY buffer	6.8 ± 2.0						1.3 ± 0.5
CCR5QTY serum	29.0 ± 8.9						2.1 ± 0.6
CCR10 native					∼5.6	∼38
CCR10QTY buffer					4.2 ± 1.4	38.5 ± 8.0
CCR10QTY serum					6.2 ± 2.4	52.7 ± 7.1

^*CCL5 is also called “Rantes,” and CXCL12 is also called “SDF1α” in the literature.

^†The K_d ∼200 nM was measured by a cell-based assay.

All QTY code designed chemokine receptors were purified from E. coli inclusion bodies and renatured in refolding buffer.