GENERAL CONSIDERATIONS OF THE USES OF SH REAGENTS 653 



hilar preparations is the penetrabihty of the SH reagent, and those reagents 

 should be chosen that have the most likelihood of reaching the systems to 

 be attacked. Thus iodoacetamide is often a better choice than iodoacetate 

 for intracellular inhibition because it is uncharged and probably enters cells 

 more readily. 



The treatment of the individual SH reagents in the following chapters 

 must be eclectic in view of the immense amount of reported work, partic- 

 ularly during the past few years. The attempt will be made to select the 

 results of those investigations done most carefully and thoroughly, and to 

 include work on the most important or interesting facets of inhibition by 

 SH reagents. A third aim is to present all the available accurate data that 

 may aid in the assessment of the specificity of these inhibitors in order to 

 use them more profitably in complex systems. 



