at the variable positions closest to the internal loop tables i ii and iil contain sequence and activity information for ribozymes designed against targets found in the hiv 1 genome the hsv genome and the rat anf gene respectively activities as kcat k m were determined by incubating 2 100nm ribozyme with approximately 1 nm radioactively labeled substrate for different times in 75 mm tris hcl ph 8 0 10 mm mgcl 2 the products are separated by denaturing polyacrylamide electrophoresis and quantitated by a beta emission scanner ambis systems san diego calif the data are treated per michaelis menton for excess enzyme specifically the negative log of the fraction substrate remaining is plotted as a function of time the resulting slope is then plotted as a function of ribozyme concentration the slope of this line is then kcat k m ribozymes which meet the strong base pair criteria for stem i are marked with a 34 i 34 in the left margin the average activity of these ribozymes is 33 u00d7 10 6 m u00b7 min which is well above the average for all the represented ribozymes 22 u00d7 10 6 m u00b7 min and the average for ribozymes not meeting this criteria 15 u00d7 10 6 m u00b7 min ribozymes which meet the strong base pair criteria for stem iii are marked with a 34 iii 34 in the left margin the average activity of these ribozymes is 28 u00d7 10 6 m u00b7 min and for those not meeting this criteria is 8 u00d7 10 6 m u00b7 min six ribozymes have the appropriate strong inner bases in both stems their average activity is 37 u00d7.