In living cells, proteins that function in the same or related pathways work co-operatively by dynamic assembling and disassembling. Especially in the sessile plant lives, biological processes, such as signal transductions and intracellular membrane trafficking, are extensively depended on the interaction of functionally-correlated proteins. Therefore, detection and determination of protein-protein interactions is a critical important approach for the characterization of protein functions.  

Pull-down assay is an in vitro method that is widely used for the confirmation or detection of physical interactions between two or more proteins. The principle of the pull-down assay is to utilize affinity ligand to capture interacting proteins.

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