Understanding the role of tyrosine in glycogenin.

We explored the molecular basis of tyrosine as the docking amino acid for the first glucose molecule during the synthesis of glycogen. The IR spectra show that the aromatic ring acts as bait to keep the position where the next glucose unit has to bind clear, by luring non-desirable molecules towards the aromatic ring. Only, α-/β-glucose shows particular affinity for the O3H and O4H moieties.