28 



1. lODOACETATE AND lODOACETAMIDE 



The evidence for a reasonably selective action of iodoacetate on muscle 

 3-PGDH relative to lactate dehydrogenase is much better. First, lactate 

 dehydrogenases from most sources are not readily inhibited (Table 1-5), 



Table 1-5 

 Inhibitions of Lactate Dehydrogenase by Iodoacetate 



" These enzymes w( 

 ** lodoacetamide. 



called lactate oxidases. 



and in no case has the enzyme been found to be nearly as sensitive as 3- 

 PGDH. The lactate dehydrogenase from beef heart contains 7-9 SH groups, 

 but only 3 of these react with ?)-mercuribenzoate in the native state and 

 none reacts with iodoacetate under the usual experimental conditions (Ny- 



