| 主权项 |
1. A method of identifying proteins, including proteins comprising posttranslational modifications, specifically associated with a target chromatin in a cell, the method comprising:
a) providing:
i) a first cell sample wherein the target chromatin is tagged by contacting the target chromatin with a tag capable of specifically recognizing and binding one or more portions of the target chromatin and wherein the tag comprises two affinity handles and a nucleic acid capable of binding a nucleic acid sequence component of the target chromatin, wherein the nucleic acid sequence component of the chromatin is normally present in the cell, andii) a second cell sample wherein the target chromatin is not tagged,wherein the first cell sample and the second cell sample are lysed; b) performing affinity purification on each lysed cell sample in (a) using a substrate capable of binding the affinity handle, wherein affinity purification of the first cell sample results in isolation of affinity handle bound to tagged target chromatin and enrichment of the target chromatin relative to affinity purification of the second cell sample not contacted with the tag; c) identifying bound proteins from (b); and d) determining the amount of each bound protein in each cell sample from (b), wherein bound proteins that are enriched in the first cell sample as compared to the second cell sample are specifically associated with the tagged chromatin in the first cell sample. |
