Table 1.

TTN estimates for several representative biocatalysts

Enzyme (organism)	Substrate	Temp. (°C)	kcat,obs (s−1)	half-life (hr)	kd,obs (s−1)	TTN	Source
enoate reductase (Yersinia bercovieri)	2-cyclo -hexenone	45	4.5	1.95	9.87 × 10−5	4.56 × 104	Chaparro-Riggers et al. (2007)
β-glucosidase (Pyrococcus furiosus)	GlcpβNp[1]	100	10.8	85	2.26 × 10−6	4.77 × 106	Kengen et al. (1993)
glucose dehydrogenase (Sulfolobus solfataricus)	D-glucose	70	74.9	45	4.28 × 10−6	1.75 × 107	[2]
subtilisin S41 (Antarctic Bacillus TA41)	s-AAPF-pNa[3]	60	264	0.16	1.24 × 10−3	2.13 × 105	Miyazaki et al. (2000)
subtilisin 3-2G7 (Antarctic Bacillus TA41)		60	553	9.43	2.04 × 10−5	2.71 × 107
cephalosporin acylase CA130 wild-type (Pseudomonas sp.)	GL-7-ACA[4]	37	12.3	68.1	2.83 × 10−6	4.34 × 106	Zhang et al. (2005)
cephalosporin acylase CA130-R121βA mutant (Pseudomonas sp.)		37	12.2	88.3	2.18 × 10−6	5.59 × 106
cephalosporin acylase CA130-K198βA mutant (Pseudomonas sp.)		37	11.7	107.5	1.79 × 10−6	6.54 × 106
cephalosporin acylase CA130-D286βA mutant (Pseudomonas sp.)		37	12.7	53.9	3.57× 10−6	3.56 × 106
glucose dehydrogenase strain 168 wild-type (Bacillus subtilis)	D-glucose	25	40.6	0.37	5.25 × 10−4	7.73 × 104	Vazquez-Figueroa et al. (2007)
glucose dehydrogenase A246V mutant (Bacillus subtilis)		25	51.8	0.31	6.08 × 10−4	8.52 × 104
glucose dehydrogenase P105S mutant (Bacillus subtilis)		25	6.1	0.52	3.73 × 10−4	1.64 × 104
glucose dehydrogenase V227A mutant (Bacillus subtilis)		25	33.1	0.67	2.89 × 10−4	1.15 × 105

^[1]p-nitrophenyl-b-D-glucopyranoside

^[2]Activity data from Lamble et al., 2003; half-life data from Giardina et al., 1986.

^[3]succinyl-LAla-LAla-LPro-LPhe-p-nitroanilide

^[4]glutaryl 7-aminocephalosporanic acid