34 

 dimethylthiazol-2-yl) -2, 5-diphenyltetrazolium-bromide; 

 (thiazolyl blue) , and 2 mg N-methyldibenzopyrazine methyl 

 sulfate (phenazine metasulfate) in 50 ml of 100 mAT glycine '] 



"■i 



buffer (without glycerol) at pH 9. Gels were incubated at 

 37°C for 10 to 20 min or at room temperature for 30 min to 

 an hour. These conditions were used unless otherwise stated 

 and were modified from the method presented by Davis (24) , 



Kinetic values 

 Shikimate dehydrogenase 



Enzyme activities were assayed f luorometrically as 

 described for SP-I and SP-II. In the forward physiological 

 direction, either DHS or NADPH was held constant at 

 saturating levels while the remaining substrate 

 concentration was varied to obtain saturation curves. In 

 the reverse of physiological direction, SHK and NADP* were 

 assayed similarly. Double reciprocal plots of the substrate 

 saturation data were used to determine the Km for each 

 substrate. 

 Dehydroquinase 



DQT activities were assayed spectrophotometrically as 

 described for SP-I and SP-II at varying concentrations of 

 DHQ to obtain saturation data, and then analyzed 

 appropriately as above to determine the Km for each protein. 



,1 



i 



