Clutch Prep is now a part of Pearson
Ch. 5 - Protein TechniquesWorksheetSee all chapters
All Chapters
Ch. 1 - Introduction to Biochemistry
Ch. 2 - Water
Ch. 3 - Amino Acids
Ch. 4 - Protein Structure
Ch. 5 - Protein Techniques
Ch. 6 - Enzymes and Enzyme Kinetics
Ch. 7 - Enzyme Inhibition and Regulation
Ch. 8 - Protein Function
Ch. 9 - Carbohydrates
Ch. 10 - Lipids
Ch. 11 - Biological Membranes and Transport
Ch. 12 - Biosignaling
Clutch Review 1: Nucleic Acids, Lipids, & Membranes
Clutch Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway
Clutch Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism
Clutch Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation
Protein Purification
Protein Extraction
Differential Centrifugation
Salting Out
Column Chromatography
Ion-Exchange Chromatography
Anion-Exchange Chromatography
Size Exclusion Chromatography
Affinity Chromatography
Specific Activity
Native Gel Electrophoresis
SDS-PAGE Strategies
Isoelectric Focusing
Diagonal Electrophoresis
Mass Spectrometry
Mass Spectrum
Tandem Mass Spectrometry
Peptide Mass Fingerprinting
Overview of Direct Protein Sequencing
Amino Acid Hydrolysis
Chemical Cleavage of Bonds
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: Edman Degradation

Practice: The peptide Leu—Cys—Arg—Ser—Gln is subject to Edman degradation. Products of the 1st cycle include:

Practice: Suppose you isolated a nonapeptide (9 amino acid residues) from a patient’s blood. Reaction of the nonapeptide with FDNB followed by acid hydrolysis produces a DNP-product with a sulfhydryl R-group, indicating that:

Practice: Treatment of the nonapeptide from the previous problem (1-1) with CNBr produces a tetrapeptide containing the N-terminal amino acid and a pentapeptide. After one round of Edman degradation on the pentapeptide, a product is produced that contained a nonpolar, aliphatic R group, meaning that the pentapeptide has:

Practice: The second and third rounds of Edman degradation on the same pentapeptide from the problem above (1-2) produced products with aliphatic alcohol groups, meaning that the pentapeptide had:

Practice: Hydrazinolysis of the same pentapeptide from the problems above produced modified amino acids & a free α-amino acid with an aromatic-alcohol group. Combining the info from these problems, the pentapeptide is most likely:

Practice: Deduce the entire sequence of the original nonapeptide using the following hint and the information from the previous four practice problems (1-1 through 1-4). Hint: The sequence of the nonapeptide using the one-letter amino acid codes reveals a relevant academic subject.