Engineering synthetic antibody binders for allosteric inhibition of prolactin receptor signaling

Table 1 Binding kinetics and loop sequence of PRL-R sABs

sAB	k _on (M ⁻¹ s ⁻¹ ) ^a	k _off (s ⁻¹ ) ^a	K _D (nM) ^a	Loop sequence
sAB	k _on (M ⁻¹ s ⁻¹ ) ^a	k _off (s ⁻¹ ) ^a	K _D (nM) ^a	L3 ^b	H1 ^b	H2 ^b	H3 ^b
A-4	No binding			HYTTPP	FYSSYI	YIYPSYGY	SYYSYYGWDYHNSSGAM
A-8	9.6 × 10⁴	5.4 × 10⁻⁴	5.6	YYSYYYPF	FSSSSM	YISPYYGS	SYGYVYWNAYSSGM
A-9	1.4 × 10⁴	3.4 × 10⁻⁵	2.5	YSSSYLL	FSSSSI	SIYSYYSS	SYDSYPWVYSYTVSGAF
A-10	1.2 × 10⁵	2.6 × 10⁻³	21	HYTTPP	FSSSYI	SISPYYGS	SYYYPEETAF

^aBinding kinetics were determined by SPR on a Biacore 2000, dissociation constant was calculated from the on and off rates.
^bRandomized loops in the Fab scaffold, L3: light chain loop 3; H1, H2 and H3: heavy chain loop 1, 2 and 3, respectively.

ISSN: 1478-811X