原核表达过程中非目标蛋白质识别与确认的方法：NRSF/REST蛋白功能结构域ZnF2-8原核表达过程中 b -内酰胺酶的确认

Escherichia coli ( E. coli ) is often used to produce recombinant proteins rapidly with high yield. However, the bacteria expresses non-target proteins unexpectedly in many cases, some of which may later be proven useful. Full characterization of these unpredicted proteins are usually expensive and time-consuming. In this study, we used E. coli to express neuron-restrictive silencer factor/RE1-silencing transcription factor (NRSF/REST) functional motif ZnF2-8, which is involved in the interaction of NRSF/REST with neuron-restrictive silencer element (NRSE/RE1) dsDNA or small non-coding dsRNA for neuron gene transcriptional repression or activation. Overexpression of a non-target protein was observed. Two-dimensional 1 H- 15 N HSQC NMR spectroscopy, X-ray crystallography and other biochemical assays were used in combination to characterize the non-target protein to be β -lactamase.