生物素酰化重組蛋白表達系統 哺乳動物表達載體pcDNA6/BioEase表達生物素酰化的融合蛋白，提供了一種簡便、高效的檢測和純化手段。BioEase標簽是含72個氨基酸殘基的肽段，體內的生物素連接酶系統（ Biotin Protein Ligase），使這段肽鏈上特定的賴氨酸殘基生物素酰化。生物素酰化的融合蛋白可以用鏈霉親和素瓊脂糖珠進行純化。

The pcDNA6-BioEase Gateway Biotinylation System provides an easy, efficient method for expressing, purifying, and detecting biotinylated recombinant proteins. The pcDNA6/BioEase-DEST vector (Figure 1) incorporates a 72 amino acid sequence from K. pneumoniae that directs in vivo biotinylation of a specific lysine residue. This K. pneumoniae tag is recognized and efficiently biotinylated in vivo by a native mammalian system similar to the enzyme Biotin Protein Ligase (BPL) in E. coli(1). Proteins produced from the pcDNA6/BioEase-DEST vector are expressed as fusion proteins to this sequence. Biotinylated fusion proteins can be purified by streptavidin agarose, detected on western blots using streptavidin-HRP or streptavidin-AP conjugates, or visualized in mammalian cells by immunofluorescence with a streptavidin-FITC conjugate (Figure 2). In addition to the 72 amino acid K. pneumoniae sequence, the pcDNA6/BioEase-DEST vector includes the following features:

 attR sites for fast and efficient recombination with any attL-flanked Gateway entry vector
 The CMV promoter for high-level expression of the recombinant fusion protein
 An enterokinase cleavage site for efficient removal of the N-terminal BioEase fusion tag