Table 1.

Parameters describing formation of the AdSS-PLP complex, reversible and tightly bound (covalently joined due to formation of the Schiff base), and effect of 1 mM vitamin C, acting as a Schiff base reducing agent.

AdSS-PLP complex	Parameter		Standard error or asymmetric confidence intervals	Conditions
reversible	IC50	9.97 µM	3.99 to 24.91 µM	Saturation with substrates
	A∞	0.02 U/mg	±0.09 U/mg	Saturation with substrates and PLP
	Ki	6.95 µM	±0.82 µM	Competition with GTP
Schiff base bound	IC50eq	0.028 µM	0.011 to 0.068 µM	In equilibrium, Saturation with IMP, Asp and PLP, no GTP
	A∞	0.08 U/mg	±0.03 U/mg
	k	0.73 min-1	±0.09 min-1
+ 1 mM Vitamin C	A∞	0.03 U/mg	±0.02 U/mg	PLP 100 µM, incubated
	k	14.47 min-1	±1.89 min-1	with AdSS, no substrates present
No vitamin C	A∞	0.12 U/mg	±0.01 U/mg
	k	0.037 min-1	±0.002 min-1