Basic Metallo-biology

Question 1

What % of proteins in cells have a metal bs

Answer 1

50%

Question 2

What is a structural example of metal use

Answer 2

Zinc finger proteins which need zinc to bind 4 residues and allow for dna-protein interaction and protein-protein

(See fr)

Question 3

Which metal is in the human superoxide dismutase active site

Answer 3

Copper

Question 4

What does sod do

Answer 4

Concerts superoxide radicals to hydrogen peroxide for ox stress

Question 5

Which enzyme converts urea to ammonia and co2 in plants fungi and bacteria

Answer 5

Urease

Question 6

What has it got in its active site

Answer 6

Di nickel site

Question 7

Why is ammonia important

Answer 7

For n source for growth

And also in h pylori it neutralises ph in stomach

Question 8

Which metals are used for electron transporting

Answer 8

Redox metals eg fe

Question 9

Which enzyme uses 2 heme fe to transport electrons to oxygen in last resp step

Answer 9

Cox

Question 10

Give example of zinc finger uses

Answer 10

Dna recognition, txn activation, protein folding/assembly

Question 11

Which large epigentic complex has a zinc finger domain and why

Answer 11

Cbpp300 to bind other tf

Question 12

What is the motif called on a lot of tf which is zinc dependant dnabd

Answer 12

Dm motif

Question 13

What does the dm motif recognise

Answer 13

Minor dna groove

Question 14

Why chaperone is used to transfer copper to sod

Answer 14

Ccs1

Question 15

What redox metals were available in the reduced environment with anaerobic bacteria years ago

Answer 15

Fe and cu because soluble in reduced environment (not in oxidised)

Question 16

Is there ions in sea water

Answer 16

No it’s metal limiting

Question 17

Which metal is seen as a relic as no human proteins use it due to lack of availability and

Answer 17

Nickel (only in some bacteria and plant urease’s)

Question 18

What is the fe acquisition evolved mech

Answer 18

Reductases comcert fe3 to fe2 (soluble and can be transported into cell)

Siderophorws in fungi/bacteria bind fe3 and allow transportation

Question 19

What does cambialistic mean

Answer 19

When enzyme can use 2 metal substrates depending on what available

Question 20

Which metals not used in eukaryotes but are in pro

Answer 20

Cobalt and nickel

Question 21

How can non biological metals like cadmium and mercury cause toxicity

Answer 21

Bind to protein and block it’s function

Displace other metals eg cadmium displaces zinc from zinc finger

Question 22

How can they bind just as well

Answer 22

Cysteine and histidine residues in proteins hve high metal ion affinity

Question 23

What was the Minamata disease

Answer 23

Methyl mercury exposure led to binding to selleno proteins in brain causing oxidative damage

Eg muscle weakness, vision liss

Question 24

What enzyme can cadmium bind and block causing ox damage

Answer 24

Sod

Question 25

What biological metal is in excess in Wilson’s disease, showing toxicity of essential metals as they bind wrong place/displace others

Answer 25

Copper excess

Question 26

Which metal has highest affinity binding so can displace best

Answer 26

Copper

Question 27

What can displace fe from fe-s clusters in fumarase enzyme in the tca cycle

Answer 27

Copper

Question 28

What is the Fenton reaction

Answer 28

Redox metals reacting with hydrogen peroxide eg cu forming hydroxyls which are free radicals = metal toxicity

Question 29

In fe deficiency, what is inserted into protoporphyrin instead and used to diagnose anemia

Answer 29

Zinc