these changes , which paralleled an increase in dna synthesis , included the expression of and linear increase in the activity of the fetal liver cell enzyme gamma-glutamyl transpeptidase , an increased production of alpha1-fetoprotein , and a change in the substrate specificity of fructose-bisphosphate aldolase to that of the fetal liver isozyme .
C0014442
enzyme
C0022173
isozyme