Abstract
Cyclophosphamide (CP; 2.5–10.0 mM) reversibly inhibits acetylcholinesterase (AChE) activity of chicken brain (58–84%) in a concentration-dependent manner, the IC
50 (the concentration causing 50% inhibition) being about 2.0 mM. Lineweaver-Burk plots indicated that the nature of this inhibition is mixed; intercept and slope replots are straight lines, showing that the inhibition is complete rather than partial. The value of
K
m for AChE is found to be 108μM, while values of
k
i and
K
i, are found to be 1.5 and 5.1 mM, respectively.
K
i, is greater than
K
I indicating that uncompetitive inhibition is predominant over noncompetitive inhibition.