Question

Explain the basic logic of how they contribute to the finding of an association between two proteins. 1. mass spectrometry, 2. immunoprecipitation analyses, and 3. co-immunoprecipitation analyses

please limit each answer to 3 sentences.

Thank you.

Answer 1

Sol:

1) Mass spectrometry(MS) is a very sophisticated and highly precise technique for characterizing, detecting, identifying, proteins and peptides by determining their mass. This technique enables to detect dynamic cell processes in spectacular detail. MS is highly sensitive, in that it could detect as little as 1 * 10-16 mol of a peptide or 10 * 10-15 mol of a protein of approximately 20000 molecular weight.

2) The immunoprecipitation technique is a technique which help isolate the antigen of interest for differernt analysis. It also provides a sensitive assay for the presence of a particular antigen in a given cell or tissue type.The procedure includes extract produced by disruption of cells is mixed with specific antibody against the antigen of interest in order to form an antigen-antibody complex. This technique can also be used in conjunction with biosynthetic radioisotope labeling to determine whether a particular antigen is actually synthesized by a cell or tissue.

3) Co-immunoprecipitation (co-IP) is a technique that is used to analyze protein–protein interactions. This technique identifies physiologically relevant protein–protein interactions by using target specific antibodies to indirectly capture proteins that are associated with specific target protein. This technique works when the tight binding of proteins involved in the complex are higher. This will help to pull multiple members of a protein complex out of solution by binding onto one member with a spcific antibody. This concept can also be called as as a "pull-down".