after 90 % inactivation , only half of the enzyme molecules bind methotrexate , and the dissociation constant for methotrexate is 40 nm as compared to 4 nm for native enzyme in solutions of 0.1 m ionic strength , ph 7.2 also , tpnh is not bound as tightly to the modified enzyme-methotrexate complex as to the unmodified enzyme-methotrexate complex .
C0014442
enzyme
C0026741
enzyme