Table 3.

Rate Data for Truncated TRs using Peptide Disulfides as Substrates.

Substrate	Rate (min−1•mM−1)
	Enzyme (octapeptide)
	mTR3Δ8 (PTVTGCUG)	DmTRΔ8 (PTPASCCS)	CeTR2Δ8 (PRTQGCCG)
Cyclic Se-peptide	260 ± 16a	499 ± 24	49 ± 4
Acyclic Se-peptide	8.2 ± 1.4b	31 ± 0.4	19 ± 3.3
Cyclic S-peptide	0.03 ± 0.002a	41 ± 1.5	136 ± 34
Acyclic S-peptide	0.02 ± 0.001a	0.04 ± 0.001	0.06 ± 0.03
Switch mutant	0.23 ± 0.012	4.6 ± 0.04	NDc
DTNB	3500 ± 230a	316 ± 79	287 ± 37
Peptide-TNB	220 ± 62	21 ± 0.45	32 ± 9

^aFrom Ref. (17)

^bThis number is slightly higher than previously reported in (17).

^cND = Not determined