Table 2.

K_m and k_cat of purified HN^a

Virus	Substrate	Purified HN		Whole virusb
		Km (mM cleavable sialic acid, pH 5.5, 37°C)	kcat (s−1)	Km (mM cleavable sialic acid)	kcat (s−1)
hPIV2	MUN	0.44 ± 0.07	49 ± 15	0.18 ± 0.04	57 ± 3.4
	NANL	0.50 ± 0.03	4.2 ± 1.1	0.47 ± 0.06	10 ± 1.7
	bFetuin	0.34 ± 0.08	8.2 + 2.2	0.40 + 0.07	1.5 ± 0.08
	bFetuin peptides	0.43 ± 0.11	10 ± 1.3	1.22 ± 0.24	8.1 ± 0.69
	hAGP	0.98 ± 0.16	16 ± 2.2	0.64 ± 0.04	4.76 + 0.72
hPIV3	MUN	4.9 ± 0.49	16 ± 1.5	8.2 ± 0.67	12 ± 2.3
	NANL	—c	—	—	—
	bFetuin	—	—	—	—
	bFetuin peptides	—	—	—	—
	hAGP	1.4 ± 0.31	3.5 + 0.62	2.5 + 0.5	1.36 ± 0.22

^ahPIV1 soluble HN K_m and specific activity were reported by Wang et al. (21).

^bData are from reference 7.

^c—, cleavage of this substrate was not measurable.