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. 2002 Dec;11(12):2848–2859. doi: 10.1110/ps.0221902

Table 2.

Kinetic parameters for wild-type and mutant aminotransferases

Aspa Phea
kcat/KM (M−1 s−1) × 10−1 kcat (s) KM (mM) kcat/KM (M−1 s−1) × 10−2 kcat (s−1) KM (mM)
Aspartate Aminotransferases
    WT 910 (13)b 159 (2)b 1.75 (0.04)b 1.19 (0.03)c n.s.c n.s.c
    T109Sc 86 (7) 180 (14) 21 (3) 3.0 (0.02) n.s. n.s.
    N297Sc 280 (12) 95 (1) 3.5 (0.2) 1.56 (0.04) n.s. n.s.
    T109S/N297Sc 120 (4) 160 (3) 12.8 (0.7) 3.3 (0.2) n.s. n.s.
    Trip 1560 (90) 13.4 (0.2) 0.086 (0.006) 23 (2) 34 (2) 15 (2)
    Grease 33 (4) 0.301 (0.004) 0.092 (0.009) 19.4 (9) 3.4 (0.03) 1.75 (0.07)
    Hex 340 (50) 7.4 (0.3) 0.22 (0.04) 370 (20) 28.9 (0.5) 0.78 (0.05)
Tyrosine Aminotransferases
    WTc 370 140 3.8 9600 250 0.26
    S109Tc 390 (70) 61 (4) 1.4 (0.7) 2200 (220) 137 (17) 0.6 (0.2)
    S297Nc 83 (8) 76 (7) 9.1 (0.1) 870 (250) 65 (20) 0.6 (0.4)
    S109T/S297Nc 130 (24) 42 (2) 2.9 (0.4) 320 (140) 131 (48) 2.5 (1.7)
    retroGrease 24 (2) 21.5 (0.9) 7.9 (0.9) 400 (30) 82 (1.4) 2 (0.2)
    retroHEX 120 (11) 30 (1) 2.6 (0.3) 14 (1) n.s. n.s.

(n.s.) No saturation.

a Conditions: 20 μM PLP, 150–200 μM NADH, 25°C. [MDH] = 0.32–2.4 nM for Asp coupled assay. [HO-HxoDH] = 0.3–3.0 μM for Phe coupled assay. Trip AATase, Hex AATase: 0.2 M TAPS at pH 8.4; 0.1 M KCl; 5 or 10 mM αKG for Trip AATase, 4 mM αKG for Hex AATase. retroHex TATase: 20 mM K phosphate at pH 7.5; Ic maintained at 0.1 M with KCl; 1 mg/mL BSA; 15 mM αKG; [L-Asp] varied from 0.5–12 mM. [L-Phe] varied from 2–24 mM. Grease AATase, retroGrease TATase: 0.2 M TAPS at pH 8.0; 0.1 M KCl; 20 mM αKG for Grease AATase, 30 mM αKG for retroGrease TATase. [L-Asp] and [L-Phe] varied from 1–40 mM. Values for Grease AATase and retroGrease TATase are reported as weighted averages from 3–5 experiments.

bFrom Gloss and Kirsch (1995).

c From Luong and Kirsch (2001).

d From Hayashi et al. (1993). Errors were not reported.