title: GSM4873669: DAPPL_Group_1_symmetric_modification; synthetic construct; OTHER
library_construction_protocol: First, human proteins were purified as GST fusions and kept on glutathione beads. Second, each protein was covalently tethered to a single-stranded DNA (ssDNA) oligo (i.e., anchor oligo) through a thiol–maleimide “click” chemistry linkage; the anchor oligos of each protein were then annealed to the a unique barcode oligo, and converted to double-stranded DNA (dsDNA) with a DNA polymerization on beads. After removal of the free DNA oligos, an aliquot of beads for each barcoded protein was mixed together to generate a protein mixture. Third, a random N-mer dsDNA library was synthesized and capped by a BsaI restriction site to allow for proximity ligation and a fixed sequence (i.e., Primer 2) for PCR priming. Fourth, to carry out the DAPPL reactions, the N-mer DNA library was incubated with the barcoded protein bead mixture, followed by stringent washing steps to remove unbound DNA. After a crosslinking step, Golden Gate Assembly reactions were performed to ligate the DNA barcodes of the proteins to their captured DNA fragments. The ligated DNA products were PCR-amplified with specific primers compatible with the Illumina NGS Systems to constructed the sequencing library. DAPPL
attributes.tag: GEO Accession
attributes.value: GSM4873669