Table 1. . Enzyme kinetics for fibroblast activation protein-mediated hydrolysis of fluorescence-quenched peptides designed from hinge regions and flanking sequences of the LTBP1-4 isoforms.

	Position	Sequence	Km (μM)	kcat (s-1)	kcat/Km (M-1s-1)
LTBP1	672–681	ISEEKGPCYR		NC
	706–715	VGKAWGPHCE		NC
	748–757†	HHVGKGPVFV		NC
	786–795†	FSREHGPGVA	10.5 ± 0.5	2.1E-0.3 ± 2.4E-0.5	208 ± 25
	797–806†	PEVATAPPEK		NC
	849–858	VPVEVAPEAS		NC
	862–871	ASQVIAPTQV		NC
LTBP2	674–683	CYRSLGPGTC		NC
	761–770†	SGALPGPAER	6.3 ± 0.4	8.8E-0.4 ± 6.2E-0.4	147 ± 108
	852–861	ATNVCGPGTC		NC
LTBP3	490–499†	FLHPDGPPKP		NC
	504–513†	ESPSQAPPPE		NC
	572–581†	SAVEIAPTQV		US
	597–606	GECVPGPPDY		NC
LTBP4	365–374	ISEAKGPCFR		NC
	420–429	EICPAGPGYH		US
	481–490†	PDPRPGPELP		NC
	494–503†	IPAWTGPEIP		US
	501–510†	EIPESGPSSG	24.2 ± 1.5	1.4E-0.2 ± 2.9E-0.3	565 ± 81
	515–524	NPQVCGPGRC		US

^†Located in the hinge region.

NC: Not cleaved under the conditions tested; US: Unable to synthesize.