Protein analysis Flashcards
What are the 3 chromatography techniques?
Size
Net charge
affinity
What is Ion exchange chromatography?
It is the separation on the basis of protein charge.
What happens to the charge of a protein if pI > pH?
there is a net positive charge and they are basic proteins
What happens to the charge of a protein if pI < pH?
there is a net negative charge and they are acidic proteins.
What are the positively charged amino acids at physiological pH?
Arginine and lysine.
What are the negatively charged amino acids at physiological pH?
Glutamate and aspartate.
What are cation exchange beads?
Beads with a net negative charge that allows for the binding of positively charged proteins.
What are anion exchange beads?
Beads with a net positive charge that allows for the binding of negatively charged proteins.
How can proteins be extracted from ion exchange beads?
by adding other charged ions that compete with proteins to bind to beads.
What sis affinity chromatography?
Chromatography that relies on the fact that proteins bind to other molecules known as ligands.
What is size exclusion chromatography?
Chromatography that separates proteins based on size. Uses beads like other chromatography forms. large Proteins travel faster through the column than the small beads.
What is the purpose of treating proteins with sodium dodecyl sulfate (SDS)?
It denatures the protein.
Why do we add a reducing agent to proteins before running on gel?
The reducing agent breaks disulfide bonds in proteins.
