Purchase Solution

Protein Folding

Not what you're looking for?

Ask Custom Question

Consider a small, natively disordered protein that exists in equilibrium with a highly ordered (folded) protein. At 37°C, the ratio of the disordered protein to ordered is 100 to 1. First, write an equilibrium expression (Keq) that describes this situation and calculate the corresponding Keq and free energy. Second, imagine that you combine the disordered protein and DNA and find that it both folds and binds the DNA with high affinity. The overall free energy of binding is calculated to be - 5.2 kcal/mol. Break down the binding to determine the actual free energy of binding of the folded protein with DNA. Finally, imagine that you're clever enough to engineer the protein to be more thermo-stable without affecting the DNA binding. In other words, the protein exists primarily in the folded form at equilibrium. What do you predict the Keq and ∆G for binding of the engineered protein to be when binding to DNA? Two hints: first draw a Schulz-energy diagram! This will guide you to the missing information you need. Second, if you didn't understand what I meant by engineering the protein, I'm suggesting that you could take the disordered protein in equilibrium with a small percentage of a folded protein and make amino acid changes such that it exists exclusively in the folded state. That's what I mean implied about it being more thermo-stable. This modified protein still binds the DNA target in the same way with the same affinity�"it just doesn't have to fold to achieve the correct binding conformation.

Purchase this Solution
Solution Summary

The equilibrium constant and free energy are calculated for protein folding.

Solution Preview

Consider a small, natively disordered protein that exists in equilibrium with a highly ordered (folded) protein. At 37°C, the ...

Purchase this Solution
Free BrainMass Quizzes
The Moon

Test your knowledge of moon phases and movement.

Intro to the Physics Waves

Some short-answer questions involving the basic vocabulary of string, sound, and water waves.

Variables in Science Experiments

How well do you understand variables? Test your knowledge of independent (manipulated), dependent (responding), and controlled variables with this 10 question quiz.

Introduction to Nanotechnology/Nanomaterials

This quiz is for any area of science. Test yourself to see what knowledge of nanotechnology you have. This content will also make you familiar with basic concepts of nanotechnology.

Classical Mechanics

This quiz is designed to test and improve your knowledge on Classical Mechanics.

View More Free Quizzes
Related BrainMass Solutions

  • Multiple choice questions in Cell Biology

    All of the following proteins interact with exposed amino acids during protein folding in the ER except: a. BiP c.

  • Protein Structure Matching Questions

    36154 Protein Structure Matching Questions Match the phrases I-VI with options A-D below.

  • In vitro translation and the production of active proteins

    These proteins might require special conditions in the cell or other proteins called "chaperones" to promote their correct folding.

  • Enzyme basic units

    There is also secondary structure in proteins determined by the amino acid sequence: the side chains of the amino acids interact with each other, resulting in particular folding patterns in the amino acid chain of the protein, for example a-helices and

  • Antibody/antigen binding

    Because the region of the antibody needed for the interaction with an antigen often involves many distant amino acids that are brought together through high order protein folding, denaturation can lead to completely or partially loss of affinity for the

  • Proteins and enzymes

    Amino acids that are near to each other in the polypeptide chain can interact (referred to as local folding) to form either alpha-helix or beta-pleated sheet which are the secondary structures of protein.

  • The effects of pH and temperature

    Both temp and pH can change the folding of the protein. If the folding is changed then the enzyme is less active. Heat and pH can cause a protein (enzyme) to denature, or unfold. To help you visualize this, think about an egg white.

  • Stress proteins

    Because of their role in regulating protein folding, practically every protein in the cell ends up bound to a heat shock protein at some point.

  • Protein Molecules: Structure and Synthesis

    Each protein chain arranges into a set of alpha-helix structural segments connected together in a globin fold arrangement. This folding pattern contains a pocket which strongly binds the heme group.

View More Related Solutions