Sections
Protein Purification
Protein Extraction
Differential Centrifugation
Salting Out
Dialysis
Column Chromatography
Ion-Exchange Chromatography
Anion-Exchange Chromatography
Size Exclusion Chromatography
Affinity Chromatography
Specific Activity
HPLC
Spectrophotometry
Native Gel Electrophoresis
SDS-PAGE
SDS-PAGE Strategies
Isoelectric Focusing
2D-Electrophoresis
Diagonal Electrophoresis
Mass Spectrometry
Mass Spectrum
Tandem Mass Spectrometry
Peptide Mass Fingerprinting
Overview of Direct Protein Sequencing
Amino Acid Hydrolysis
FDNB
Chemical Cleavage of Bonds
Peptidases
Edman Degradation
Edman Degradation Sequenator and Sequencing Data Analysis
Edman Degradation Reaction Efficiency
Ordering Cleaved Fragments
Strategy for Ordering Cleaved Fragments
Indirect Protein Sequencing Via Geneomic Analyses

Concept #1: Anion-Exchange Chromatography

Example #1: Circle the peptide below that elutes last during anion-exchange chromatography if the pH is ~7?

Practice: Which amino acid elutes last from an anion-exchange column at physiological pH?

Practice: Use the chart to determine which tripeptide would elute last from an anion-exchange column at pH = 9.3.

Practice: Which type of ion exchange chromatography would be best to separate a mixture of histidine and arginine? 

            His: pK1 = 1.8, pK2 = 9.3, pKR = 6.0                     Arg: pK1 = 1.8, pK2 = 9.0, pKR = 12.5

Practice: Stationary resin compounds with carboxymethyl (CM) and diethylaminoethyl (DEAE) groups are shown below. Indicate which one is likely used in a cation exchange column and which one is likely used in an anion exchange column. Considering the following peptide at pH 7, should DEAE or CM groups be used as the stationary resin to purify the peptide? 

Peptide: G-R-W-K-R-H