Thus , the two substrates of this enzyme are 5 , 6 , 7 , 8 - tetrahydrobiopterin and NADP , .
NADP 's 3 products are biopterin .
Thus , the two substrates of this enzyme are 5 , 6 , 7 , 8 - tetrahydrobiopterin and NADP , whereas its 3 products are biopterin .