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Biochemistry & Molecular Biology;
Abstract:
The use of non-proteases for the selective removal of protecting groups from peptides and glycopeptides is described. The N-terminal deprotection of peptides can be achieved by the hyrolysis of the phenylacetyl (PhAc) amide blocking group catalyzed by penicillin G acylase. On the other hand, the lipase-mediated hydrolysis of n-heptyl (Hep) and 2-bromoethyl esters allows for the liberation of the C-terminal carboxy group. The selective C-terminal deprotection can be applied advantageously for the construction of acid- and base-sensitive polyfunctional O-glycopeptides. In all cases the enzymatic reactions are completely selective and proceed under mildest conditions (pH 7-8, r.t. to 37-degrees-C) without damaging the various other functionalities present in the complex substrates.