5: Protein Purification
Isolation and analysis methods, chromatography, electrophoresis.
LibreTexts reference: Protein Purification
Cell Disruption Techniques Identification
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Which one of the following cell disruption techniques correspond to the description 'Grinding of the cells by hand to disrupt the cell walls.'.
Types of Column Chromatography
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Which one of the following types of column chromatography correspond to the description 'hydrophobic-based separations for protein characterization'.
Identification of Macromolecules in Gel Electrophoresis Processes
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Which one of the following types of macromolecules correspond to the gel component or process 'ultraviolet light (UV) visualization'.
Determining Net Charge of Proteins at Given pH
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Isoelectric Point Problem
| Protein Name | isoelectric point (pI) | molecular weight |
|---|---|---|
| Fumerase (Fum) | 7.6 | 48.5 |
The protein in the table (above) is placed in a buffer solution with a pH of 6.5.
What is the correct net charge on the Fum protein at pH of 6.5
Protein Migration Direction Based on Isoelectric Point
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Isoelectric Point Problem
A mixture of two proteins are to be separated by isoelectric focusing.
| Protein Name |
Isoelectric Point (pI) |
Molecular Weight |
|---|---|---|
| G3P Dehydrogenase (GDH) | 8.3 | 36.0 |
| Histone (His) | 10.8 | 15.0 |
Both protein samples are placed into a gel with a constant pH of 12.0. The gel is then placed into an electric field.
In which direction will each protein in the table migrate at pH 12.0?
Estimating Protein Molecular Weight from SDS-PAGE Migration
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Gel Migration Problem
In this task, data from an SDS-PAGE experiment, where proteins are separated based on molecular weight, is provided. The gel results table below shows some standard proteins with known molecular weights and one unknown protein.
| Protein Name | Molecular Weight (kDa) |
Migration Distance (cm) |
|---|---|---|
| Streptavidin (Stp) | 13.2 | 3.44 |
| Avidin (Av) | 16.9 | 3.24 |
| Agglutinin (Agg) | 22.0 | 3.03 |
| Urease A (Ure) | 26.5 | 2.88 |
| G3P Dehydrogenase (GDH) | 36.0 | 2.63 |
| Ovalbumin (Ova) | 45.0 | 2.45 |
| Pyruvate Kinase (PK) | 60.0 | 2.22 |
| Unknown | ? | 2.79 |
Estimate the molecular weight of the unknown protein by comparing its gel migration distance with those of the standards.