    2.4.1.11 | UDP-alpha-D-glucose + [(1->4)-alpha-D-glucosyl]n = UDP + [(1->4)-alpha-D-glucosyl]n+1 |
glycogen synthase performs a stepwise SNi-like mechanism, involving the concerted departure of the leaving group and the attack of the incoming nucleophile, via ion-pair intermediate 1,5-anhydro-D-arabino-hex-1-enitol or its tautomeric form, 1,5-anhydro-D-fructose, bound at the catalytic site. Even in the absence of a glucosyl acceptor, glycogen synthase promotes the formation of the cationic intermediate, which, by eliminating the proton of the adjacent C2 carbon atom, yields 1,5-anhydro-D-arabino-hex-1-enitol, overview |
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