BCH210H1 Lecture Notes - Lecture 30: Atp Synthase, Atp Hydrolysis, Integral Membrane Protein

29 views3 pages
Lecture 30: ATP Synthesis
ATP Synthase
F0 is the integral membrane protein unit that anchors the enzyme in the inner
mitochondrial membrane
- a subunits creates a channel where protons will enter and bind to c
subunit in the membrane (10-15 of them) which forms a ring and rotates
when protons bind to them
Protons flow through a subunit causing a rotation in the ring c subunits of F0
F1 is the peripheral protein (matrix) unit that carries out the catalytic synthesis of ATP
- 3 a and 3 B subunits (Bs are responsible for ATP synthesis)
- Y subunit that runs from membrane component to the middle of the protein (y rotates that induce
conformational change of B)
- Delta at the top and epsilon in the middle that help attachment of lollipop to membrane
Stator (considered membrane component d) holds the membrane and lollipop together
Conformational changes in the F1 B subunits are responsible for ATP synthesis
ATP is then exported out of the matrix to cytosol for use in the rest of the cell by translocase
Boyer’s Binding Change Mechanism
Each B subunit changes between 3 states (they catalyze ATP separately)
- Open or Empty/exit
- Loose with ADP and Pi bound
- Tight with ATP bound
1. Loose state ADP + Pi can bind conformational change through y touching c
2. Tight state ATP is formed through ADP and Pi combination + H2O another conformational change
3. Open/empty state ATP released
Constant flow of the H+ and rotation of gamma changes the conformation of each subunit
independently
All three subunits will all be in different states
A subunits also go through conformational change but do not participate in catalysis (part of complete
enzyme, binding to other two B)
ATP synthase is reversible
Imaging techniques can be used to visualize rotation of the F1 unit
ATP hydrolysis can be used to reverse the reaction mechanism
ATP synthase could be used to drive proton transport via ATP hydrolysis
and drive rotation (proton pumping)
Add his-tag to anchor F1 to Ni-NTA and label y with GFP adding ATP + H2O, it binds to tight state,
hydrolysis takes (ADP + Pi) place with conformational change in B that also rotates y
ATP Synthase
The B-subunit is responsible for ATP synthesis in the matrix of the mitochondria
As protons flow through the c ring, rotation results in a conformational change in B via the y subunit
3 H+ are pumped per ATP molecule synthesized in cytosol (human ATP synthase)
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in
thaanya10 and 40172 others unlocked
BCH210H1 Full Course Notes
49
BCH210H1 Full Course Notes
Verified Note
49 documents

Get access

Grade+
$40 USD/m
Billed monthly
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
10 Verified Answers
Class+
$30 USD/m
Billed monthly
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
7 Verified Answers

Related Documents

Related Questions