Expressed enzymatic ligation proteins

The development of EPL has facilitated the production of large protein targets, but the requirement of specific N-terminal amino acids at the ligation site (cysteine [7], selenocysteine ]66J) reduces the general utilization of this method. Recently, we introduced a novel approach that we named expressed enzymatic ligation (EEL) for the semisynthesis of larger and chemically modified proteins that combines the advantages of the EPL with those of the substrate mimetic... 

Machova, Z., von Eggelkraut-Gottanka, R., Wehofsky, N., Bordusa, E., and Beck-Sickinger, A. G. (2003) Expressed enzymatic ligation a new approach for the synthesis of chemically modified proteins, Angew. Chem. Int. Ed. 42, 4916-4918. 

Over the last four decades, synthetic non-enzymatic oligonucleotide ligations have been explored as potential models for the evolution of replicating systems on the early Earth [2-11]. These studies have explored ligation reactions that occur on a template without protein/enzymatic catalysis. Such systems have both provided mechanisms for the early evolution of biopolymer catalysts and placed limits on template directed ligation. More recently, the lure of antisense molecules capable of disrupting specific gene expression has resulted in the exploration of backbone-modified nucleic acids [12-33]. 

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