The TGF-β mimic TGM4 achieves cell specificity through combinatorial surface co-receptor binding

Table 1 Summary of ligand–receptor binding affinities.

TGM ligand	Measurement	TβRI	TβRII	mCD44	hCD44
TGM1-FL	SPR	90 ± 1 nM	0.61 ± 0.01 µM^a
TGM4-FL	SPR	5.0 ± 0.1 nM	116 ± 2 µM
TGM1-D45	ITC			30 (9, 68) nM^b	122 (73, 195) nM^b
TGM4-D45	ITC			20 (7, 41) nM^b	78 (40, 136) nM^b

Affinity measurements of full-length (FL) TGM1 and TGM4 for TβRI and TβRII were measured by Surface Plasmon Resonance (SPR); affinities of D4-5) of the two proteins for CD44 of mouse (mCD44) and human (hCD44) were measured by Isothermal Titration Calorimetry (ITC).
^aValue previously reported by Mukundan et al (Mukundan et al, 2022).
^bValues in parenthesis represent estimated upper and lower bounds by the Sedphat fitting algorithm.