Conformational change GudangMovies21 Rebahinxxi LK21

      In biochemistry, a conformational change is a change in the shape of a macromolecule, often induced by environmental factors.
      A macromolecule is usually flexible and dynamic. Its shape can change in response to changes in its environment or other factors; each possible shape is called a conformation, and a transition between them is called a conformational change. Factors that may induce such changes include temperature, pH, voltage, light in chromophores, concentration of ions, phosphorylation, or the binding of a ligand. Transitions between these states occur on a variety of length scales (tenths of Å to nm) and time scales (ns to s),
      and have been linked to functionally relevant phenomena such as allosteric signaling and enzyme catalysis.


      Laboratory analysis


      Many biophysical techniques such as crystallography, NMR, electron paramagnetic resonance (EPR) using spin label techniques, circular dichroism (CD), hydrogen exchange, and FRET can be used to study macromolecular conformational change. Dual-polarization interferometry is a benchtop technique capable of providing information about conformational changes in biomolecules.
      A specific nonlinear optical technique called second-harmonic generation (SHG) has been recently applied to the study of conformational change in proteins. In this method, a second-harmonic-active probe is placed at a site that undergoes motion in the protein by mutagenesis or non-site-specific attachment, and the protein is adsorbed or specifically immobilized to a surface. A change in protein conformation produces a change in the net orientation of the dye relative to the surface plane and therefore the intensity of the second harmonic beam. In a protein sample with a well-defined orientation, the tilt angle of the probe can be quantitatively determined, in real space and real time. Second-harmonic-active unnatural amino acids can also be used as probes.
      Another method applies electro-switchable biosurfaces where proteins are placed on top of short DNA molecules which are then dragged through a buffer solution by application of alternating electrical potentials. By measuring their speed which ultimately depends on their hydrodynamic friction, conformational changes can be visualized.
      "Nanoantennas" made out of DNA – a novel type of nano-scale optical antenna – can be attached to proteins and produce a signal via fluorescence for their distinct conformational changes.


      Computational analysis


      X-ray crystallography can provide information about changes in conformation at the atomic level, but the expense and difficulty of such experiments make computational methods an attractive alternative. Normal mode analysis with elastic network models, such as the Gaussian network model, can be used to probe molecular dynamics trajectories as well as known structures. ProDy is a popular tool for such analysis.


      Examples


      Conformational changes are important for:

      ABC transporters
      catalysis
      cellular locomotion and motor proteins
      formation of protein complexes
      ion channels
      mechanoreceptors and mechanotransduction
      regulatory activity
      transport of metabolites across cell membranes


      See also


      Database of protein conformational diversity
      Protein dynamics
      The Database of Macromolecular Motions (molmovdb)


      References




      External links


      Frauenfelder, H. New looks at protein motions Nature 338, 623 - 624 (20 April 1989).
      Sensing with electro-switchable biosurfaces

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    conformational change | Semantic Scholar

    conformational change | Semantic Scholar

    | Overall conformational change | Download Scientific Diagram

    | Overall conformational change | Download Scientific Diagram

    PPT - Conformational Change in Proteins PowerPoint Presentation - ID ...

    PPT - Conformational Change in Proteins PowerPoint Presentation - ID ...

    PPT - Conformational Change in Proteins PowerPoint Presentation, free ...

    PPT - Conformational Change in Proteins PowerPoint Presentation, free ...

    Lights, Conformational Change… Action! | Advanced Photon Source

    Lights, Conformational Change… Action! | Advanced Photon Source

    Site-specifically identified conformational change. a Details of ...

    Site-specifically identified conformational change. a Details of ...

    Conformational switching upon change of concentration. The transition ...

    Conformational switching upon change of concentration. The transition ...

    Conformational change induced by heat-treatment Differences between the ...

    Conformational change induced by heat-treatment Differences between the ...

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    Solved How does binding of o, trigger a conformational - Chegg

    How does binding of o, trigger a conformational change in the quaternary structure of Hb? Select one: a. none of these O b. crowding of o, binding site forces a conformational change c. all of these O d. O, binding causes flattening of the heme; resulting movement of residues attached to heme cause conformational change O e.

    Solved How do most motor proteins ensure their movements are

    O Choose one: O A. They couple a conformational change to the formation of an ATP molecule from ADP and Pi. O B. Their asymmetrical structures support movement in only one direction. O C. They couple a conformational change to a thermodynamically unfavorable reaction. O D. They couple a conformational change to the hydrolysis of an ATP molecule ...

    Solved The induced fit conformational change in hexokinase

    The induced fit conformational change in hexokinase occurs when- ATP binds. glucose-6-phosphate is released. ADP is released. the allosteric site is saturated. glucose binds. Your solution’s ready to go!

    Solved How does a noncompetitive inhibitor affect enzyme - Chegg

    Multiple Choice Binding to an allosteric site causes a conformational change. ces Binding to an allosteric site reverses the direction of a reaction. Binding to the active site induces a conformational change. Binding to an allosteric site causes the enzyme to be secreted

    Solved (4 of 4) The T to R state conformational change of - Chegg

    (4 of 4) The T to R state conformational change of hemoglobin can occur when oxygen binds at any one of the four heme groups of hemoglobin. can occur when ionic bonds stabilizing the T-state are broken. would be less likely to occur if the covalent bond between the proximal His and the heme were broken. would be more likely to occur if Lys C5 were mutated to a Glu.

    Topic 2: Concept Map - Part 2 Name: Membrane | Chegg.com

    Question: Topic 2: Concept Map - Part 2 Name: Membrane Transport A. Moves molecules down gradient B. Active Transport C. Passive Transport D. Moves solutes from an area of LOW concentration to an area of HIGH concentration of solute using a protein which undergoes a conformational change E. Osmosis Moves molecules against gradient G. Moves water from an …

    Solved elp Which conformational change is the first step of - Chegg

    Question: elp Which conformational change is the first step of chymotrypsinogen activation? O a formation of a peptide bond between arginine 15 and isoleucine 16 Ob formation of hydrogen bonds between aspartate 194 and isoleucine 16 O c. formation of the cavity for aromatic and bulky nonpolar groups by residue movements d. formation of an ionic bond between isoleucine

    Solved Which of the following best describes how cAMP - Chegg

    cAMP binds to PKA's catalytic subunits, causing a conformational change that leads to increased activity. cAMP phosphorylates PKA, causing a conformational change that leads to increased activity. cAMP binds to PKA's regulatory subunits, causing a conformational change that releases the catalytic subunits to carry out phosphorylation

    Solved In reaction 1 of the citrate cycle, oxaloacetate and - Chegg

    The conformational change that occurs in citrate synthase following oxaloacetate binding is a very small and subtle conformational change. Here’s the best way to solve it. Solution

    Solved What conformational change in the myosin head is - Chegg

    ATP hydrolysis leads to a conformational change that causes the release of calcium from the myosin head. Question 15 (6 points) Identify the correct label for A, B, C, and D in the figure.