Fig. 5-9. Substrate protection against thermal 

 inactivation of S-proteins. Purified enzyme was 

 incubated at 50°C for 2 or 5 min without substrate added 

 or 5 min with NADP^ or SHK added, assayed at 25°C and 

 compared to unheated extract activity. Conditions for 

 assay were the same as described in Fig. 5-8. SP-I 

 results are shown in panel A and SP-I I results are shown 

 in panel B. 



