570 



2. ANALOGS OF ENZYME REACTION COMPONENTS 



moderately in mice from both deficiency and injections of deoxypyridoxol 

 (Dietrich and Shapiro, 1953 a). Despite the lowered levels of transaminase 

 and decarboxylase, cysteine desulfhydrase (also dependent on pyridoxal-P) 

 is not affected by deoxypyridoxol, due to the fact that the apodesulfhydrase 

 has little affinity for deoxypyridoxol-P, no inhibition of the binding of py- 

 ridoxal-P being observed (Dietrich and Borries, 1956). 



600 



500 



400 



300 



200 



^ 100 



LIVER 

 KIDNEY 



TIME (DAYS) 



Fig. 2-20. Effects of deoxypyridoxol given intraperitoneally at 



150 mg/kg/day on the aspartate: a-ketoglutarate transaminase of 



mouse tissues. (From Shapiro et al., 1953.) 



Serine biosynthesis from formate and glycine, involving serine transhy- 

 droxymethylase, is dependent on pyridoxal-P. The incorporation of for- 

 mate-C^* into serine in chick liver extracts is much reduced when these 

 are obtained from deoxypyridoxol-treated animals, the depression being 

 around 50% and reversible with pyridoxal-P in vitro (Sakami, 1955). Renal 



