Automatic testing of enzyme modifiers by the flow-gradient technique

The potential of the flow-rate gradient technique for the automatic testing of enzyme modifiers is demonstrated by using the acetylthiocholine/acetylcholinesterase system. Modifier concentration gradients are created in the enzyme flow by establishing flow-rate gradients via computer control of the peristaltic pump used to propel the modifier solution stream. A single solution of each modifier and a single experiment is sufficient to obtain information about the modifier effect and to quantify the modifier/substrate ratio above which it is detected. 33 substances were tested and their effects on the enzyme system quantified by spectrophotometric detection. The procedure provides a rapid, simple means for studying modifiers affecting any enzyme system.