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10 Cards in this Set
- Front
- Back
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In column chromatography, the first material of a protein sample to elute has what affinity?
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Things that have the lowest affinity will elute first.
Things that have the highest affinity to the column will come out last as they are more attracted to the column. |
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With regards to ion exchange chromatography, rule of thumb for what binds to the column: below the pI of a protein, it will be _________ charged ; above the pI of a protein, it will be _______ charged.
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POSITIVELY charged BELOW their pI ; no charge at pI ; negatively charged above their pI
remember, the ion exchange column is named after what it ATTRACTS. |
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With regards to ion exchange chromatography, rule of thumb for what binds to the column: [above/below] the pI of a protein, it will be negatively charged ; [above / below] the pI of a protein, it will be positively charged.
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above pI will be negatively charged ; below pI will be positively charged.
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In gel filtration chromatography/ size exclusion/ gel permeation, size is used to separate. What elutes first?
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Larger protein molecules elute first because they can go around (don't have to go thru) the beads (which have their own convoluted pathways supposedly).
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What is protein specific ligand (affinity chromatography)?
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Substrate or antibody bound to beads themselves. When you put in protein mixture, protein that don't bind to ligand will travel easily down column. Afterwards, putting a solution of ligand or something else that binds stronger to the protein of interest, makes it elute.
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True or False: Purification of a protein leads to an increase in activity.
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FALSE. Activity is units. Activity should not increase but slightly decrease. What SHOULD increase is the specific activity which is units/ mg,
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With gel electrophoresis, SDS binds to proteins in proportion to their sizes, causing proteins with higher MW to migrate [more quickly / more slowly].
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more slowly
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What type of protein characterization technique separates proteins on the basis of their isoelectric points?
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Isoelectric focusing. Setup a pH gradientona gel (gel tube shown here). The proteins migrate to the point where they have no charge (their pI).
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Peptides were initially sequenced by stepwise chemical degradation, which often yielded only a few residues from the amino terminus. Latest methods determine an entire peptide sequence from a single _________________ analysis.
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mass spectrometric
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True or False: Electrospray ionization of Large Molecules was how mass spectrometry of macromolecules (proteins) was achieved by a VCU researcher.
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True
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