1. ATP Powered Pumps
By Adam Attebery

2. Introduction General information about ATP activated pumps
Four different classes of ATP activated transmembrane proteins
Function and examples of each
Mechanism of each

3. ATP Powered Pumps
Transport various small particles against concentration gradient
All ATP powered pumps are transmembrane with ATP binding site on the cytosolic face of membrane.

4. 4 classes of pumps P-class pump V-class proton pumps
Sodium potassium pumps and calcium pumps
V-class proton pumps
Plasma membrane of osteoclasts
F-class proton pumps
Inner mitochondrial membrane
ABC superfamily
Flippase

9. P-class Pumps
All contain two identical catalytic α subunits with ATP binding sites
In general P-class pumps are ion pumps that move the molecules against concentration gradient

10. ATP-Powered Ion Pumps
Ionic composition of the cytosol usually differs greatly from the extracellular fluid
Cytosolic pH is kept near 7.2 regardless of the extracellular pH

13. F-class and V-class Pumps
Structures are similar to one another
Not related to P-class Pumps
All known F and V-class pumps transport only protons
V-class pumps maintain low pH at the cost of ATP
F-class pumps function to power the synthesis of ATP

14. ABC Superfamily
Specific to a single substrate or a family of substrates
Ions, sugars, amino acids, phospholipids, peptides, polysaccharides, or even proteins
Structural organization consisting of 4 domains
2 transmembrane domains
2 cytosolic ATP-binding domains

17. Summary Four classes of transmembrane proteins
Require the hydrolysis of ATP
Two examples of P-class ATPases
Calcium pump of SR in muscle
Sodium Potassium pump
Phosphorylation of the alpha subunits and a conformational change are essential for coupling ATP hydrolysis to transport ions

18. Summary V- and F-class ATPases transport protons exclusively
V-class pumps maintain pH
F-class pumps are found in mitochondria and produce ATP

19. Summary All ABC superfamily proteins contain four core domains
2 transmembrane domains
Form pathway for solute movement
Determine substrate specificity
2 cytosolic ATP-binding domains

20. Summary
ABC superfamily transport a wide array or substrates including:
Toxins
Drugs
Phospholipids
Peptides
Proteins

21. Summary According to the flippase model
Molecules diffuse into cytosolic leaflet
Flip to exoplasmic leaflet in an ATP powered process
Finally diffuses from membrane into extracellular space