1. Protein purification and analysis Flashcards

1
Q

What is chromatography used for?

A

preparative separation of proteins

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2
Q

What physical and chemical differences make proteins different?

A

charge
size
affinity for ligand
solubility
hydrophobicity
thermal stability

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3
Q

What is column chromatography?

A

a protein mixture is poured into a column with a porous mixture

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4
Q

How does column chromatography work?

A

proteins with a lower affinity for the solid will wash off and proteins with a higher affinity will remain longer

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5
Q

What is ion exchange chromatography?

A

using a column, separate proteins that are electrically attracted to the mixture

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6
Q

Explain size exclusion chromatography

A

larger molecules pass more freely and will come out of the column firtst

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7
Q

Explain binding affinity chromatography

A

mixture added to a column containing a polymer bound ligand specific for protein of interest

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8
Q

What type of chromatography improves efficiency?

A

high performance liquid chromatography

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9
Q

What is the lambert-Beer law?

A

absorbance = EconcentrationL

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10
Q

What is the specific activity?

A

the number of enzyme units per mg of total protein

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11
Q

What is electrophoresis separation?

A

electric field pulls proteins through a gel matrix according to their charge

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12
Q

What does the gel do in electrophoresis?

A

hinders mobility of proteins based on size and shape

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13
Q

What does the SDS do?

A

facilitates unfolding and gives all proteins a uniformly negative charge

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14
Q

What is SDS-PAGE separation based on?

A

size of proteins

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15
Q

Which proteins move faster in SDS-PAGE?

A

small proteins

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16
Q

Define electrophoresis

A

method used to visualize and characterize purified proteins

17
Q

What four things can electrophoresis be used to estimate?

A

number of different proteins
degree of purity
isoelectric point
approximate molecular weight

18
Q

In a marker graph of electrophoresis, which way to the molecular sizes go?

A

large to small

19
Q

What is isoelectric focusing used for?

A

determining the pI of a protein

20
Q

What is 2D-electrophoresis?

A

combines isoelectric focusing and SDS-PAGE

21
Q

What are the two methods used to determine protein sequencing?

A

Edman degradation
mass spectrometry

22
Q

What is Edman Degradation?

A

rounds of n-terminal modifiaction, cleavage, and identification

23
Q

What is mass spectometry?

A

identifies the mass of a peptide to know what amino acid was cleaved off

24
Q

What are proteases?

A

perform hydrolytic cleavage of peptide bonds

25
Q
A