lec 27 - Lecture 27 Regulation of protein function(Ch 3 p...

Info icon This preview shows pages 1–14. Sign up to view the full content.

View Full Document Right Arrow Icon
Lecture 27: Regulation of protein function (Ch. 3; p. 88-92) Regulation by changes in conformation: Allostery + cooperativity Common regulators: Calcium GTP Phosphorylation/dephosphorylation
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
“Allos” – other “Stereos” – solid/3 dimension Allostery Binding of one ligand influences binding of another ligand in a different region of the protein !In fact, ligand interaction ALWAYS influences protein conformation to a certain extent!
Image of page 2
A A A B B B Allostery Positive: Change in conformation spreads throughout the protein
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
A A B Allostery Negative: Change in conformation spreads throughout the protein B
Image of page 4
Consider a polypeptide as a network of interactions involving the covalent bonds of the backbone and all the non-covalent interactions between the various amino acids. Protein-protein binding (but also binding to other molecules) implies formation of new non-covalent bonds, which in turn will influence the overall “equilibrium” of interactions, and can thus in some cases propagate changes throughout the whole protein. Here comes a simplified model (imaginary example) to help you visualize this concept. Allostery
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Allostery
Image of page 6
Allostery
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Allostery
Image of page 8
Allostery
Image of page 9

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Allostery
Image of page 10
Allostery
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Cooperativity B A A B B A B A B A B A Binding of the 1st A induces changes in conformation that influence binding of B, but alters the conformation of the second subunit, favoring binding of the 2 nd A 1 st binding difficult 2 nd binding easy Regulation of multimers much more efficient ! Cooperativity can also be negative!
Image of page 12
monomer dimer tetramer 10% 90%
Image of page 13

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 14
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern