. Author manuscript; available in PMC: 2009 Dec 15.

Published in final edited form as: Biochem J. 2008 Dec 15;416(3):357–364. doi: 10.1042/BJ20071132

Table 1.

Kinetic parameters determined for various HTLV-1 protease forms^a

		Buffer A_____________			Buffer B_
Enzyme form	Substrate	K_m(mM)	k_cat (s^-1)	k_cat/K_m(mM^-1s^-1)	k_cat/K_m(mM^-1s^-1)
HTLV-1 125 PR	KTKVL↓VVQPK	0.063 ± 0.004^b	10.0 ± 0.2^b	158.7 ± 10.6^b	5.41 ± 0.17^c
HTLV-1 125 PR	KTKVF↓VVQPK	0.049 ± 0.006^b	16.4 ± 0.9^b	334.7 ± 44.9^b	4.16 ± 0.06^c
His-HTLV-1 125 PR	KTKVL↓VVQPK	0.088 ± 0.013	0.0020 ± 0.0001	0.022 ± 0.003	No cleavage^d
His-HTLV-1 125 PR	KTKVF↓VVQPK	0.116 ± 0.014	0.021 ± 0.001	0.180 ± 0.023	No cleavage^d
HTLV-1 120 PR	KTKVL↓VVQPK	0.034 ± 0.003	0.150 ± 0.004	4.4 ± 0.4	0.81 ± 0.03^c
HTLV-1 120 PR	KTKVF↓VVQPK	0.014 ± 0.001	0.160 ± 0.001	11.7 ± 0.4	1.03 ± 0.08^c
HTLV-1 116 PR	KTKVL↓VVQPK	No cleavage^d			No cleavage^d
HTLV-1 116 PR	KTKVF↓VVQPK	Residual activity^e			No cleavage^d

Measurements were performed at least in triplicate sets providing values within the experimental errors. A representative set is given the table. No activity was observed for His-HTLV-1 116 PR, HTLV-1 115 PR and His-HTLV-1 115 PR forms in buffer A or in buffer B.

These data are taken from Ref. (8).

These values were determined using first-order kinetic conditions ([S] << K_m)

No hydrolysis was observed neither at low nor at high protease concentration.

Residual activity was observed when the substrate was incubated with 3.1 μsM protease in assay conditions.