. 2007 Mar;143(3):1385–1397. doi: 10.1104/pp.106.091736

Table I.

Steady-state properties of the kinetic model of Suc and glycogen metabolism of diazotrophically cultivated Anabaena sp. PCC 7120 cells

Reaction Name	V_max	K_m or K_i		Net Flux	Comment	Reference
	nmol mg protein⁻¹ min⁻¹	mm		nmol min⁻¹ mg fresh weight⁻¹
R1: Hexokinase	8.8	K_{m Glc}	0.2	1.050	Clamped concentrations of ATP and ADP	This study; Smith and Moore (1981)
Hexose + ATP → hexose-P + ADP		K_{m Fru}	7.5
Hexose + ATP → hexose-P + ADP		K_{i ATP}	1.0
R2: SPS-A	2.8	K_{m Fru-6P}	0.4	0.090	Biosynthesis of Suc-6P	This study; Cumino et al. (2002)
UDP-Glc + Fru-6P → Suc-6P + UDP		K_{m UDP-Glc}	1.3
UDP-Glc + Fru-6P → Suc-6P + UDP		K_{i UDP}	2.0
R3: SPS-B	1.05	K_{m Fru-6P}	2.5	0.490	Biosynthesis of Suc-6P	This study; Cumino et al. (2002)
XDP-Glc + Fru-6P → Suc-6P + XDP		K_{m ADP-Glc}	3.0
(X = U or A)		K_{m UDP-Glc}	4.0
		K_{i ADP}	4.0
R4: SPP	4.4	K_{m Suc-6P}	0.35	0.580	Net production of Suc	Cumino et al. (2001)
Suc-6P → Suc + Pi		K_{i Suc}	80
R5: SuS	3.5	K_{m Fru}/K_{m UDP-Glc}	52/2.7	−0.090	Flux is in direction of Suc cleavage	Porchia et al. (1999)
XDP-Glc + Fru → Suc + XDP	0.7	K_{m Fru}/K_{m ADP-Glc}	4.2/1.3
(X = U or A)	1.8	K_{m Suc}/K_{m UDP}	303/1.25
	0.7	K_{m Suc}/K_{m ADP}	305/1.15
R6: INV	1.8	K_{m Suc}	10	0.295	Irreversible Suc hydrolysis	Vargas et al. (2003)
Suc + water → Glc + Fru
R7: Hexose-P mutase	2.8	K_{m Glc-1P}	0.2	−0.490	Flux is in direction of Glc-1P production	Pearce and Carr (1969)
Glc-1P → Glc-6P
R8: Hexose-P isomerase	4.2	K_{m Fru-6P}	0.25	0.190	Flux is in direction of Fru-6P production	Pearce and Carr (1969)
Glc-6P → Fru-6P		K_{m Glc-6P}	5
R9: UGPase	52	K_{m Glc-1P}/K_{m UTP}	0.1/0.3	0.000	The mass action ratio equals the K_eq and the change in free energy is zero at steady state. Under these conditions, the net flux is null.	This study
UDP-Glc + PPi → Glc-1P + UTP	130	K_{m UDP-Glc}/K_{m PPi}	0.1/0.2
R10: AGPase	7.8	K_{m Glc-1P}/K_{m ATP}	0.07/0.1
ADP-Glc + PPi → Glc-1P + ATP	24	K_{m ADP-Glc}/K_{m PPi}	0.4/0.03	−0.490	Flux is in direction of ADP-Glc production, involved in glycogen and Suc biosynthesis	Ballicora et al. (2003)