Purine Synthesis

Front 1

N1 of Purine

Back 1

Aspartate Amine

Front 2

C2 and C8 of Purine

Back 2

Formate (2 Different)

Front 3

N3 and N9

Back 3

Glutomine Amide (2 different)

Front 4

N7, C5, and C4

Back 4

Glycine (strongly suggest whole incorporation)

Front 5

RXN Step 1

Back 5

Ribose-5-Phosphate is phosphorylate by Ribose phosphate pyrophosphokinase. RXN is ATP driven and forms PRPP.

Front 6

Step 2

Back 6

Amidophosphoribosyl transferase adds N9 from glutamine to C1 of PRPP forming PRA. This is flux control step.

Front 7

Step 3

Back 7

GAR synthetase adds C4, C5, and N7 from glycine w/ ATP hydroylsis. Only rexn where more than one purine ring atom is aquired and this forms GAR

Front 8

Step 4

Back 8

GAR transformylase adds C8 from the formyl donor N10-formyl-THF, forming FGAR. RXN directed by sulfonamide.

Front 9

Step 5

Back 9

FGAM synthetase adds N3 from a 2nd glutamine and is coupled w/ ATP hydrolysis

Front 10

Step 6

Back 10

Purine imidazole ring closed by AIR synthetase causing tautomeric shift and requires ATP, this will form AIR

Front 11

Step 7

Back 11

C6 from bicarbonate is added by AIR carboxylase. Enzyme is made from 2 proteins, PurE and PurK, rxn is coupled with ATP hydroylsis.

Front 12

Step 8

Back 12

N1 from a aspartate is added by SAICAR synthetase and is coupled w/ ATP hydrolysis

Front 13

Step 9

Back 13

SAICAR cleaved by adenylosuccinate lyase releasing fumarate and forms AICAR

Front 14

Step 10

Back 14

C2 added by N10-formyl-THF w/ AICAR transformylase and is directed by sulfonamide, this will form FAICAR

Front 15

Step 11

Back 15

Ring closure w/ IMP cyclohydralase releasing water and IMP.

Front 16

To make AMP

Back 16

IMP -->adenylosuccinate w/ adenylosuccinate synthetase -->adenylosuccinate lyase will release fumarate and AMP

Front 17

To make GMP

Back 17

IMP --> XMP w/ IMP dehydogenase -->GMP with GMP synthetase (ATP hydrolysis)