Protein Structure Channels

Question 1

protein functions

Answer 1

enzymes, defense, support, transport, storage, movement, regulations

Question 2

what is a structural motif?

Answer 2

short segments of proteins that spacially close but not adjacent

Question 3

examples of tertiary structure?

Answer 3

aB horseshoe fold

WD40 repeat

Question 4

what proteins are stable and what are dynamic?

Answer 4

stable- enyzmes

dynamic- signalling

Question 5

is every AA residue essential for function

Answer 5

no

Question 6

what are K channels?

Answer 6

neural communication and computation, muscle, lifes transitors

Question 7

experimental methodologies of K channels

Answer 7

ion conductance- patch clamping
x ray crystallography
SAR

Question 8

structure of VG K channels

Answer 8

highly conserved signature motif - TVGYG, 4 subunits, 2 inner helices

Question 9

subunit structure of VG K channels

Answer 9

v shaped tetramer, 158 residues, selectivity filter, cavity, internal pore

Question 10

structure of selectivity filter of K channel

Answer 10

4 layers of carbonyl oxygen (VGYG)

1 layer hydroxyl oxygen (Thr)

4 binding sites

Question 11

why are K channels conductive?

Answer 11

pos K ions prefer neg charge pore, lowered dehydration energy,

Question 12

why are K channels selective?

Answer 12

filter structure accoms K ion
cannot shrink to bind smaller ions
higher energy cost

Question 13

mechanism of voltage gating

Answer 13

depolarisation rotates arg sensors towards extracellular

glycine hinges gate open

Question 14

types of vg inactivation

Answer 14

N type- n ball plugs pore

C type- localized constriction of channel pore

Question 15

how do neg charges effect conductance?

Answer 15

increase conductance by raising local K+ conc