Site‐Specific Introduction of Sialic Acid into Insulin

More gain, less pain: A new long-acting insulin (see structure) was created by the enzymatic introduction of sialyllactose into mutant insulins. The glycosylation site was introduced into the insulin by point mutation without loss of biological activity. The experimental results with mice clearly demonstrated that the introduction of a sialic acid residue is crucial in prolonging glucose-lowering activity in the blood.