This 2D lane is the same Michaelis-Menten-style binding model as the 3D version, viewed from directly above: sugar donors (small dots) drift across the lane, bind an open glycosyltransferase site (hexagon) within its capture radius, wait out a conversion time proportional to 1/elongation-rate, then leave as a completed glycan (larger dot) and free the site again.
chain_i(t+1) = chain_i(t) + 1 if donor bound & elongation event
v = Vmax·S / (Km·30 + S), Km = 1/affinity, Vmax = kcat·enzymes
- Sugar donors — activated nucleotide-sugars (UDP-GlcNAc, GDP-fucose) supplying the monosaccharide unit.
- Glycosyltransferase sites — Golgi enzyme active sites that catalyze addition of one specific sugar to the growing chain.
- Donor affinity — how tightly a given donor sugar binds its transferase before the transfer reaction fires; raises the effective capture radius and bind probability.
- Chain elongation rate — how quickly a bound sugar is added and the enzyme frees up for the next donor.
Glycan structures on antibodies (like the core-fucose on IgG) directly control immune effector function, which is why biopharma companies engineer CHO cell glycosylation pathways to tune therapeutic antibody potency.