Characterization of thimet oligopeptidase and neurolysin activities in B16F10-Nex2 tumor cells and their involvement in angiogenesis and tumor growth

Table 1 Proteolytic activity of B16F10-Nex2 supernatant and recombinant enzymes on FRET peptides

Abz-peptidyl-EDDnp	Specific activity (nmoles/min/mg protein)
Abz-peptidyl-EDDnp	B16F10-Nex2	rTOP	rNeurolysin
GFSPFRQ	2.7 ± 0.6	100 ± 9.8	5.5 ± 1.0
GFSPFR	0.6 ± 0.1	21 ± 4.2	4.4 ± 0.5
GFSIFRQ	0.6 ± 0.1	14 ± 4.4	1.6 ± 0.2
GFPPFRQ	0	0	0
NKPRRPQ	0.4 ± 0.4	29 ± 3.3	58 ± 8.3
RPPGFSPFRQ	1.8 ± 0.1	51 ± 5.5	8.8 ± 0.7
rRL	0	0	0

B16F10-Nex2 supernatant and recombinant enzymes were incubated with fluorogenic substrates (20 μM) in 50 mM Tris-HCl, pH 7.4 at 37°C. Hydrolysis was followed by measuring the fluorescence at λem. = 420 nm and λex. = 320 nm. Results are expressed as means ± SD.

ISSN: 1476-4598