Label-free detection microarray for novel peptide ligands screening base on MS–SPRi combination

Peptides ligands with high affinity and high specificity towards specific targets is catching a good deal of interests in biomedical field. Traditional peptide screening procedure involves selection, sequencing and characterization and each step is time-consuming and labor-intensive. The combination between different analytical methods could provide an integrated plan for efficient peptide screening. We report herein a label-free detection microarray system to facilitate the whole one-bead-one-compound (OBOC) peptide screening process. A microwell array chip with two identical units can trap the candidate peptide beads in one-well-one-bead manner. Peptides on beads were photo-released in situ in the well and partly transferred to two identical chips for Surface Plasmon Resonance imaging (SPRi), and peptide left in the bi-unit microwell array chip was remain for in situ single bead sequencing by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Using the bi-unit imprinted chip system, affinity peptides towards AD protein were efficiently screened out both qualitatively and quantitatively from 104 candidates. The method provides a universal solution for high efficiency and high throughput ligands screening. Using the label free microarray chip system, affinity peptides towards target protein were efficiently screened out both qualitatively and quantitatively from high throughput candidates. The method provides a universal solution for high efficiency ligands screening. [Display omitted] •Label-free microarray system for peptide ligand screening was developed.•MALDI-TOF-MS and SPRi are integrated by the system.•The throughput is multiplied by the bi-unit imprinted microarray.•Novel peptide sequences towards AD protein is reported.