Glycogen synthase

Glycogen synthase (GS) converts glucose to glycogen. It takes short polymers of glucose and converts them into long polymers one by one into a polymeric chain for storage as glycogen.

Chemical equation

$UDPG + Glucose \rightarrow UDP + Glycogen$

Rate equation

MWC model (Monod-Wyman-Changeux model) is used to model the reaction mechanism of this enzyme.. Glc6P activates GS by binding to an allosteric site of this enzyme.

$\frac{K_{cat,r}[GS]n\frac{[UDPG]}{K_{UDPG}} \left( 1 + \frac{[UDPG]}{K_{UDPG}} + \frac{[ATP]}{K'_{r,ATP}} \right)^{n-1}}{\left( 1 + \frac{[UDPG]}{K_{UDPG}} + \frac{[ATP]}{K'_{t,ATP}} \right)^n L_{0} \left( \frac{1 + \frac{[Glc6P]}{K_{t,Glc6P}} + \frac{[ATP]}{K_{t,ATP}} }{1 + \frac{[Glc6P]}{K_{r,Glc6P}} + \frac{[ATP]}{K_{r,ATP}} } \right)^n + \left( 1 + \frac{[UDPG]}{K_{UDPG}} + \frac{[ATP]}{K'_{r,ATP}} \right)^n }$

Parameter values

Parameter	Value	Units	Organism	Remarks
$n$	4	Dimensionless	Rabbit muscle
$K_{cat,r}$	1004	$min^{-1}$	Rabbit muscle
Total[GS]	$3 \times 10^{-3}$	mM
L	0.25</math>	mM
$K_{UDPG}$	0.72	mM	Rat muscle
$Kr_{Glc6P}$	$6.76 \times 10^{-002}$	mM	Rat muscle
$Kt_{Glc6P}$	0.29	mM	Rat muscle
$K_{r,ATP}$	4.94	mM	Rat muscle
$K_{t,ATP}$	2.33	mM	Rat muscle
$K'_{r,ATP}$	15.92	mM	Rat muscle
$K'_{t,ATP}$	3.93	mM	Rat muscle