Lecture 5 - Protein folding
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (19 张)
Disulfide bonds can be reversibly broken by reducing with
beta-mercaptoethanol
Noncovalent bonds in a protein can be disrupted by
urea
Tertiary interactions are important in determining the
secondary structure of proteins
Tertiary interactions are interactions between
residues that are far apart in the sequence
Protein denaturation can be observed by measuring the change in
optical rotation, viscosity, and UV absorption
Proteins are denatured by
• Heat • Detergents • pH changes • Hydrophobic organic compounds • Salts • Guanidinium chloride • Urea
How does heat denature proteins?
By disrupting non-covalent interactions
How do detergents denature proteins?
By interfering with hydrophobic interactions
How does pH denature proteins?
by altering ionization states of amino acids
How do hydrophobic organic compounds denature proteins?
By interfering with hydrophobic interactions of the protein by interacting with water
How does guanidinium chloride denature proteins?
By attracting to the peptide backbone and side chains and screening favorable interactions that might stabilize the protein
How does urea denature proteins?
By hydrogen bonding to peptide bonds and weakening intermolecular bonds and interactions, weakening the overall secondary and tertiary structure
Proteins fold due to the energy gain of going from the
denatured to the folded state
As temperature increases, ΔG
decreases
The transfer of a nonpolar group from an aqueous environment to the protein’s nonpolar interior is _______ driven.
entropically
A partial unfolding of the structure
destabilizes the remaining structure
The essence of protein folding is the tendency to
retain partly correct intermediates.
In globular proteins, the average length of an alpha helix is greater than _______ residues
15
Protein folding/unfolding is not all or nothing. It takes place through
transient intermediates