Protein purification

purifiedpurificationisolateisolatedpurifyaffinity resinsexpressing and purifyingisolatesisolatingisolation
Protein purification is a series of processes intended to isolate one or a few proteins from a complex mixture, usually cells, tissues or whole organisms.wikipedia
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Host cell protein

Host cell proteins
Several preparative purifications steps are often deployed to remove bi-products, such as host cell proteins, which poses as a potential threat to the patient's health.
During the purification process, the majority of the HCPs are removed (>99%), but residual HCP amounts remain in the distributed products, such as monoclonal antibodies (mAbs), antibody-drug-conjugates (ADCs), therapeutic proteins, vaccines, and other protein-based biopharmaceuticals.

Protein

proteinsproteinaceousstructural proteins
Protein purification is a series of processes intended to isolate one or a few proteins from a complex mixture, usually cells, tissues or whole organisms. Analytical purification produces a relatively small amount of a protein for a variety of research or analytical purposes, including identification, quantification, and studies of the protein's structure, post-translational modifications and function.
Proteins may be purified from other cellular components using a variety of techniques such as ultracentrifugation, precipitation, electrophoresis, and chromatography; the advent of genetic engineering has made possible a number of methods to facilitate purification.

Lysis

lysecell lysislysed
Also proteases are released during cell lysis, which will start digesting the proteins in the solution.
In molecular biology, biochemistry, and cell biology laboratories, cell cultures may be subjected to lysis in the process of purifying their components, as in protein purification, DNA extraction, RNA extraction, or in purifying organelles.

Dialysis

kidney dialysisrenal dialysisdialysis machine
Subsequently, ammonium sulfate can be removed using dialysis.
This can be used to purify proteins of interest from a complex mixture by removing smaller proteins and molecules.

CHAPS detergent

CHAPS
A detergent such as sodium dodecyl sulfate (SDS) can be used to dissolve cell membranes and keep membrane proteins in solution during purification; however, because SDS causes denaturation, milder detergents such as Triton X-100 or CHAPS can be used to retain the protein's native conformation during complete purification.
It is used as a non-denaturing detergent in the process of protein purification and is especially useful in purifying membrane proteins, which are often sparingly soluble or insoluble in aqueous solution due to their native hydrophobicity.

Proteolysis

proteolyticprotein degradationpolyprotein
If the protein of interest is sensitive to proteolysis, it is recommended to proceed quickly, and to keep the extract cooled, to slow down the digestion.

QPNC-PAGE

David E. GarfinJürgen Horstquantitative native PAGE
An important non-denaturing electrophoretic procedure for isolating bioactive metalloproteins in complex protein mixtures is quantitative native PAGE.

Cell biology

cytologycell biologistcellular biology
Protein purification is a series of processes intended to isolate one or a few proteins from a complex mixture, usually cells, tissues or whole organisms.

Tissue (biology)

tissuetissuesbiological tissue
Protein purification is a series of processes intended to isolate one or a few proteins from a complex mixture, usually cells, tissues or whole organisms.

Biological activity

bioactivebiologically activebioactivity
Separation steps usually exploit differences in protein size, physico-chemical properties, binding affinity and biological activity.

Lactase

LactaidLCTlactase enzyme
Examples include the preparation of commercial products such as enzymes (e.g. lactase), nutritional proteins (e.g. soy protein isolate), and certain biopharmaceuticals (e.g. insulin).

Soy protein

Soy protein concentratesoyprotein
Examples include the preparation of commercial products such as enzymes (e.g. lactase), nutritional proteins (e.g. soy protein isolate), and certain biopharmaceuticals (e.g. insulin).

Biopharmaceutical

biologicsbiopharmaceuticalsbiologic
Examples include the preparation of commercial products such as enzymes (e.g. lactase), nutritional proteins (e.g. soy protein isolate), and certain biopharmaceuticals (e.g. insulin).

Insulin

insulin geneINShuman insulin
Examples include the preparation of commercial products such as enzymes (e.g. lactase), nutritional proteins (e.g. soy protein isolate), and certain biopharmaceuticals (e.g. insulin).

Post-translational modification

posttranslational modificationpost-translational modificationspost-translational
Analytical purification produces a relatively small amount of a protein for a variety of research or analytical purposes, including identification, quantification, and studies of the protein's structure, post-translational modifications and function.

Pepsin

pepsinogenpep''sinpepsin a
Pepsin and urease were the first proteins purified to the point that they could be crystallized.

Urease

urease-positive
Pepsin and urease were the first proteins purified to the point that they could be crystallized.

Sonication

Ultrasonic homogenizerultrasonicationsonicator
Depending on how fragile the protein is and how stable the cells are, one could, for instance, use one of the following methods: i) repeated freezing and thawing, ii) sonication, iii) homogenization by high pressure (French press), iv) homogenization by grinding (bead mill), and v) permeabilization by detergents (e.g. Triton X-100) and/or enzymes (e.g. lysozyme).

French pressure cell press

french cell pressFrench pressFrench pressure cells
Depending on how fragile the protein is and how stable the cells are, one could, for instance, use one of the following methods: i) repeated freezing and thawing, ii) sonication, iii) homogenization by high pressure (French press), iv) homogenization by grinding (bead mill), and v) permeabilization by detergents (e.g. Triton X-100) and/or enzymes (e.g. lysozyme).

Triton X-100

octoxynolTritondetergent
A detergent such as sodium dodecyl sulfate (SDS) can be used to dissolve cell membranes and keep membrane proteins in solution during purification; however, because SDS causes denaturation, milder detergents such as Triton X-100 or CHAPS can be used to retain the protein's native conformation during complete purification. Depending on how fragile the protein is and how stable the cells are, one could, for instance, use one of the following methods: i) repeated freezing and thawing, ii) sonication, iii) homogenization by high pressure (French press), iv) homogenization by grinding (bead mill), and v) permeabilization by detergents (e.g. Triton X-100) and/or enzymes (e.g. lysozyme).

Lysozyme

LYZmuramidaselysozymes
Depending on how fragile the protein is and how stable the cells are, one could, for instance, use one of the following methods: i) repeated freezing and thawing, ii) sonication, iii) homogenization by high pressure (French press), iv) homogenization by grinding (bead mill), and v) permeabilization by detergents (e.g. Triton X-100) and/or enzymes (e.g. lysozyme).

Protease

proteasespeptidaseproteinase
Also proteases are released during cell lysis, which will start digesting the proteins in the solution.

Protease inhibitor (biology)

protease inhibitorprotease inhibitorsproteinase inhibitor
Alternatively, one or more protease inhibitors can be added to the lysis buffer immediately before cell disruption.

Deoxyribonuclease

DNasestreptodornaseDNAase
Sometimes it is also necessary to add DNAse in order to reduce the viscosity of the cell lysate caused by a high DNA content.