230 



JJdHr AND LIFE 



weight of lO"'. From such experiments we conchide that K is equal 

 to approximately 5 X lO-'*^' moles per liter. This relationship is 

 shown graphically in Fig. 8. Such a plot produces a curve that has 

 a constant slope of 3.0 X 10~' molar, a value which is in reasonable 

 agreement with the calculated enzyme concentration of 3 X 10— " M. 

 The fact that one obtains a straight line from such a plot suggests 

 that luciferase has one active site for light production and that one 

 molecule of LAMP combines with this site. Also the value of K 

 obtained by extrapolation of / to (infinite L-AMP concentration) 

 is in good agreement with the calculated K values (21) . 



LOG('%,) 



Fig. 9. Initial flash IiciglU uitli \aiying amoiiiu of cn/yinc. The upper curve 



is tlic flash response due to the addition of LH.AMP. I lie lower curve is the 



response to All' and 1. 11.. The ratio of the enzyme to these substrates is given 

 along the abcissa. 



