20 L. F. LELOIR, C. E. CARDINI VOL. 12 (1953) 



TABLE IV 



THE ACETYLATION OF GLUCOSAMINE 



Complete system: 2 ^moles of glucosamine, 4 /imoles of ATP, 0.05 ml of i M sodium acetate, 

 0.05 ml of 0.1 M cysteine, 0.05 ml of 0.2 M sodium citrate of pH 7, o.i ml of CoA solution, 0.05 ml 

 of o.i M magnesium chloride and 0.2 ml of crude dialyzed enzyme. Final volume, 0.7 ml. Incubated 

 2 hours at 37°, 



ixmoles of acetylglucosamine formed 



Complete system 0.38 



No glucosamine 0.025 



No CoA 0.075 



No ATP 0.025 



No Mg++ 0.070 



TABLE V 



THE PHOSPHORYLATION OF GLUCOSAMINE 



Complete system as in Table III, but without CoA. The difference in glucosamine or acetyl- 

 glucosamine content between samples incubated with an without ATP was considered to be due to 

 phosphorylation. The estimations were carried out after precipitation of proteins and phosphoric 

 esters with zinc sulphate and barium hydroxide. 



^ , umoles of substrate phosphorylated 



Substrate ' y f y 



No Mg++ With Mg++ 



Glucosamine 0.8 i.So 



Acetylglucosamine o o 



TABLE VI 



THE ACETYLATION OF GLUCOSAMINE PHOSPHATE 



Complete system as in Table III. The acetylglucosamine content of the supernatants after zinc 

 sulphate-barium hydroxide precipitation was considered as free acetylglucosamine. 



r- , . , Time of incubation /Ainoles of acetylglucosamine formed 



{minutes) Total Free 



Glucosamine 



Glucosamine-6-phosphate 



TABLE VII 



THE ACETYLATION OF THE "GLUCOSAMINE" ESTER 



The "glucosamine" ester was obtained by incubation during 3 hours at 30° of 2 /nnoles each of 

 glutamine and hexose-6-phosphate with the purified enzyme. The controls contained the same 

 substances plus glucosamine (0.5 ^moles) or glucosamine-6-phosphate (i /imol), and the reaction was 

 stopped at < = o. The acetylating system described in Table III was then added. 



umoles of acetylglucosamine formed 



"Glucosamine!' ester 0.21 



Control with glucosamine 0.20 



Control with glucosamine-6-phosphate 0.31 



References p. 22. 



