Hexose-6-phosphate isomerase

The enzyme Hexose-6-phosphate isomerase converts Glucose 6-phosphate (Glc6P) into its isomer Fructose 6-phosphate (Fru6P). Isomers have the same molecular formula, but the atoms of each molecule are arranged differently.

Chemical reaction

$Glc6P \rightleftharpoons Fru6P$

Rate equation

Reversible competitive inhibition with Ery4P, 6PG and FBP.

$\frac{V_{mf}\frac{[Glc6P]}{K_{Glc6P}} - V_{mr} \frac{[Fru6P]}{K_{Fru6P}} }{ 1 + \frac{[Glc6P]}{K_{Glc6P}} + \frac{[Fru6P]}{K_{Fru6P}} + \frac{[ERY4P]}{K_{ERY4P}} + \frac{[6PG]}{K_{6PG}} + \frac{[FBP]}{K_{FBP}} }$

Parameters

Parameter	Value	Organism	Remarks
$V_{mf}$	1.2 $\pm$ 0.2 mM	HeLa cell line	3 cell assays are prepared
$K_{eq}$	651
$Km_{Glucose}$	0.1
$Km_{ATP}$	1.1
$Km_{Glc6P}$	$2e^{-002}$
$Km_{ADP}$	3.5