De novo design protein binders for MBP and GST tags.

Maltose-binding protein (MBP) and glutathione S-transferase (GST) are widely used solubility-enhancing protein tags, typically employed to address various issues related to protein expression and purification. The detection of these tags are usually achieved through binding of corresponding antibodies. Designing low-cost binders as alternatives to antibodies is of great significance. This study employed a de novo design approach, starting with a large number of protein scaffolds and screening out 6 candidate binders targeting MBP and 4 candidate binders targeting GST based on scoring functions. Flow cytometry low-affinity selection and biolayer interferometry (BLI) quantitative results showed that MBP and GST can interact strongly with one or several binders, exhibiting nanomolar binding. Among them, LZMB3 has a binding dissociation constant (K _D ) of 54.05 ± 1.46 nM, while LJGB3 and LJGB4 have K _D values of 105.4 ± 1.812 nM and 437.9 ± 17.69 nM, respectively.
Competing Interests: Declaration of competing interest The work described has not been submitted elsewhere for publication, and all the authors listed have approved the manuscript. There are no conflicts of interest associated with this work.
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