A Protein Group is a collection of proteins identified by a set of peptides. In details, a Protein Group:

• is represented by a master (or typical) protein
• contains a collection of peptides identifying this master protein
• contains a collection of proteins having the sameset of peptides
• contains a collection of proteins having a subset of peptides

A Protein Group is quite similar to a Mascot protein hit, but operates at the Context level.

Protein groups are obtained when running the Protein Grouping algorithm on a given context.

1. Right-click on the User context of your choice (for which protein grouping has been executed) in the MSIExplorer window and select “Browse→Protein groups” in the context sensitive menu
2. Browse Protein Groups in the ContextExplorer window

Master protein is represented by

1. Right-click on the protein group (typical) of your choice in the ContextExplorer window and select “View Protein” in the context sensitive menu
2. Then the Protein Group window show details about this typical protein
3. If you select another protein from the sameset/subset tabs, the outline view showing peptides will update accordingly.