pull down技术

合集下载
  1. 1、下载文档前请自行甄别文档内容的完整性,平台不提供额外的编辑、内容补充、找答案等附加服务。
  2. 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
  3. 3、如文档侵犯您的权益,请联系客服反馈,我们会尽快为您处理(人工客服工作时间:9:00-18:30)。
பைடு நூலகம்
GST
(glutathione-sepharose beads) 35S-labled cell lysate
GST
GST Protein X Interact at 40C
Microfuge to collect complexes
GST Protein X
Analyze by SDSPAGE
Lane1. Marker Lane2. GST-protein X Lane3. GST
The GST Fusion protein pull-down technique (Kaelin et al.1991) uses the affinity of GST for glutathione-coupled beads to purify interacting proteins from a solution of non interacting proteins.
Incubation, 40C, 2h Centrifugation,40C
Precleared cell lysate + glutathione agarose beads + GST
Detection of Protein-Protein Interactions Using the GST Fusion Protein Pull-down Technique
Bacterially expressed glutathione S-transferase (GST)fused proteins are used as probes to perform direct measure of protein-protein interactions and for affinity purification.
an epitope; 2) Cell in culture can be transfected with a plasmid encoding the target protein to
increase the abundance; 3) To control the specificity of binding, the best is the inclusion of a GST fusion
123
autoradiograph
The schema of a GST pull-down experiment
Two general uses :
To identify novel interactions between a fusion (or probe) protein and unknown (or target) proteins;
protein with a mutated interaction domain, 4) To test for binding between the putative protein and GST.
Method
Preclearing the cell lysate--- Incubation, 40C, 2h Centrifugation,40C
The GST fusion protein probe is expressed and purified from bacteria; In parallel, a cell lysate (which can be 35S-labled or unlabled) is prepared;
The GST fusion protein probe and the cell lysate are mixed, in the presence of glutathione-agarose beads and incubate the mixture to allow protein associations to occure;
cell lysate + glutathione agarose beads + GST
supernatant
End-over-end mixing
Probing the cell lysate---
Precleared cell lysate + glutathione agarose beads + GST
The proteins are resolved by SDS-PAGE, and processed by Western blotting, autoradiography or protein staining.
GST Protein X
(glutathione-sepharose beads) 35S-labled cell lysate
By centrifugation, collect the GST fusion probe protein and any associated molecules;
The complexes are washed and can be eluted from the beads with excess free glutathione or boiled directly in SDS-PAGE buffer;
To confirm suspected interactions between the probe protein and a known proteins.
antibodies to the target protein, or: 1) the 35S-labeled in vitro translated protein, or the target protein can be tagged with
1) The protein concentrations, 2) Is the probe protein normally expressed in that particular cell or tissue? 3) Is the goal to compare different types of cell populations?
相关文档
最新文档