isozyme 4 of p-450 differed markedly from isozyme 2 in that it catalyzed prostaglandin hydroxylation at substantial rates in the absence of cytochrome b5 , was regiospecific for position 19 of all three prostaglandins , and had an order of activity of pga1 greater than pge1 greater than pge2 .
C0033554
prostaglandins
C0002335
pge1