Purification of proteins

20/03/02

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Table of Contents

Purification of proteins
Where to start with purification?
Raw material
Break down of raw material (homogenization)
Cellular fractionation
Centrifugation can be used to separate cellular sub-fractions
Simple centrifugation
Differential centrifugation
Simple centrifugation (of a spherical particle)
Separation of Cell components by differential centrifugation
Complex centrifugal separation.
Equilibrium centrifugation
Equilibrium densities for organelles 
Protein solubilization
Protein solubilization
End result after tissue break down
Low resolution purification techniques
Salt fractionation
Salt fractionation
PPT Slide
Fractional precipitation with organic solvents.
Polyethylene glycol (PEG) precipitation
Heat treatment
Isoelectric precipitation
PPT Slide
Recommended Reading:
High resolution purification techniques
Ion exchange chromatography
Ion exchange resins
Ion exchange chromatography
Ion exchange chromatography
SephadexTM Ion Exchangers
Choice of ion exchange resin
Choice of buffer
Eluting the target protein
High performance liquid chromatography (HPLC)
HPLC
Reverse-phase HPLC
Uses of reverse-phase HPLC
Hydrophobic interaction chromatography (HIC)
 
Author: AG Clark/J Horsfield 

Email: alan.clark@vuw.ac.nz

Home Page: http://www.vuw.ac.nz/~clarkag

HPLC
Reverse-phase HPLC
Uses of reverse-phase HPLC
Hydrophobic interaction chromatography (HIC)
Isoelectric focussing and chromatofocussing.
Chromatofocussing
Gel filtration chromatography
PPT Slide
Rationale for gel filtration
Applications of gel filtration
Affinity chromatography
Rationale for affinity chromatography
Affinity chromatography - the matrix.
Affinity chromatography - the ligand.
Ligands:
Overexpression of a protein from a cloned gene
Overexpression of a protein from a cloned gene
Bacterial protein expression
Fusion proteins
Fusion proteins
Recovery of fusion proteins
Eukaryotic overexpression of genes
Affinity recovery of proteins that have been overexpressed in bacteria:
Method for affinity recovery
Removal of the vector protein…..
….and re-purification of the target protein.
“Tagged” proteins.
Some examples of tags:
Some examples of tags:
Advantages of tagged proteins