| 摘要 |
One-pot biotransformations give oligo(γ-L-Et-Glu) decorated with selected amine-functionalized end-groups at C-termini with a first process controlling the end group structure of peptides synthesized by protease catalyzed peptide synthesis, and a second process incorporating end-groups that can be used directly or after further modification as polymerizable entities. Papain, bromelain, α-chymotrypsin, Multifect P-3000 and Purafect prime 4000L are used as catalysts for oligomerization of γ-L-(Et)2-Glu in the presence of mono functional amines. The series of amine nucleophiles (NH2—R, acyl acceptors) mimic phenylalanine in that they possess aromatic rings linked to amine groups by one or more methylenes. Generally, addition of increased quantities of NH2—R from 0 to 30, 50 and 70 mol % with respect to γ-L-(Et)2-Glu results in decreased %-yield but increased mol % of NH2—R end-capped oligo(γ-L-Et-Glu)-NH—R (determined by NMR). Irrespective of the protease used, 2-thiophene methyl amine (TPMA) gave the highest fraction of oligo(γ-L-Et-Glu)-NH—R chains. l-phenylalanine and L-histidine did not produce end-capped oligo(γ-L-Et-Glu) and, inn contrast, L-phenylalanine analogs benzylamine (BzA) and L-phenylalaminol (F—OH), both of which lack the α-carboxyl group, gave substantial quantities of oligo(γ-L-Et-Glu)-F—OH, or -BzA chains. The promiscuity of proteases can be exploited to create a diverse family of desired end-functionalized oligopeptides. MALDI-TOF spectra recorded of oligo(γ-L-Et-Glu) with amine nucleophiles showed molecular ions that affirmed the formation of corresponding NH2—R functionalized oligo(γ-L-Et-Glu). |
