N-terminal extensions ("tags") have proven valuable for producing peptides using high throughput recombinant expression technologies. However, the applicability is hampered by the limited options for specific and efficient proteases to release the fully native sequence without additional amino acids in the N-terminal. Here we describe the Escherichia coli (E. coli) expression, purification and characterization of engineered variants of Xaa-Pro dipeptidyl aminopeptidase (Xaa-Pro-DAP) derived from Lactococcus lactis for cleavage of Gly-Pro dipeptide extension in the N-terminal of glucagon and glucagon-like peptide 1 (GLP-1(7-37)). By single amino acid substitution in the Xaa-Pro-DAP protease, significantly higher product yields were achieved. The combination of HRV14 3C protease and engineered Xaa-Pro-DAP is suggested for obtaining native N-terminal of peptides.

中文翻译：

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工程Xaa-Pro二肽基氨基肽酶可从融合蛋白中特异性切割胰高血糖素和胰高血糖素样肽1。

N末端延伸（“标签”）已被证明对于使用高通量重组表达技术生产肽是有价值的。然而，由于特异性和有效的蛋白酶释放完全天然序列而在N-末端没有额外氨基酸的有限选择限制了其适用性。在这里，我们描述了大肠杆菌（E. coli）的表达，纯化和表征，从乳酸乳球菌衍生的Xaa-Pro二肽基氨基肽酶（Xaa-Pro-DAP）的工程变体，用于在N-末端的Gly-Pro二肽延伸区进行切割。胰高血糖素和胰高血糖素样肽1（GLP-1（7-37））。通过Xaa-Pro-DAP蛋白酶中的单个氨基酸取代，可以实现更高的产品产量。