Action of Yeast Lactate Dehydrogenase 

 Table 2. Further kinetic data for yeast lactate dehydrogenase 



Values of V/e, K^ and Ai4 obtained by double reciprocal method (see text). Experiments were carried 

 out at 22'C and at pH 7-2. 



543 



equations may be proposed as representing the mechanism of lactate dehydro- 

 genase. 



E + S ^ ES 



A-,, 



ES->E' + P 



A-3 



E' ^E" 

 E" + A-^E + AHo 



(1) 



(2) 

 (3) 



(4) 



where E represents the oxidized form of the enzyme, ES the enzyme-substrate 

 complex, E' the reduced form of the enzyme, in which the flavin mono- 

 nucleotide moiety is reduced, E" another reduced form, in which the proto- 

 haem moiety is reduced, S the substrate, A the hydrogen acceptor, P the 

 product and ki_^ the rate constants. 



A cknowledgemen t 



We are indebted to Prof. H. Tamiya for his valuable criticism in this 

 work. This work was supported by a grant from the Ministry of Education. 



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