Metalloproteins 1

Question 1

What are the therapeutic elements?

Answer 1

Pt, Au, Li, Sb

Question 2

What are non-essential toxic elements?

Answer 2

Be, Al, As, Cd, Hg, Ti, Pb

Question 3

What are essential trace elements?

Answer 3

Co, Cr, Cu, F, I, Mn, Mo, Ni, Se, V, Zn

Question 4

Essential major elements?

Answer 4

Fe, Ca, Mg, Na, Cl, K, S, P, Si

Question 5

is Arsenic a non-metal, metalloid or metal?

Answer 5

Metalloid

Question 6

Inductive Coupled Plasma - Mass Spectrometry (ICP-MS) can detect what?

Answer 6

all metals, all metalloids and some non-metals. Including lots of nonessential elements

Question 7

How do non-essential elements get into the human body?

Answer 7

Food, Water, Environment, Products

Question 8

What is the key metalloid in the drugs which treat leishmania?

Answer 8

Sb (antimony) - Meglumine antimoniate

Question 9

What is the key metal used in one product to act as an antimicrobial, insecticide, wood preservative, textile additive and marine ship paint?

Answer 9

Sn (tin) - Tributyltin (Sn(IV))

Question 10

Why aren’t Zn, Mg or Ca involved in oxidation/reduction reactions.

Answer 10

Because Mg and Ca have an s valance orbital and so would be unstable at any other charge, thus they can not give or take any electrons. Zn also only have its s orbitals available for reactions.

Question 11

Why is Aluminum toxic?

Answer 11

Al 3+ resembles Fe 3+ and can also bind to Mg 2+ binding sites

Question 12

Why is Beryllium toxic?

Answer 12

Be 2+ can bind to Mg 2+ binding sites. It is the most toxic element.

Question 13

Why is Cadmium toxic?

Answer 13

Cd 2+ can bind to Zn binding sites in proteins

Question 14

Why is Mercury toxic?

Answer 14

Hg + and Hg 2+ can react in the body to form methyl-mercury which impairs neurological development.

Question 15

Why is lead toxic?

Answer 15

Pb 2+ interferes in the activity of various enzymes and the central nervous system.

Question 16

Why are ingested radioactive compounds so dangerous?

Answer 16

Some metal isotopes like 90 Sr will be miss-incorporated into the bones in lieu of Ca 2+ and cause long term radioactive damage.

Question 17

Why are Arsenate (As IV) and (As III) toxic?

Answer 17

As IV is toxic because it is an analogue of phosphate groups but cannot carryout its functions.

As III is toxic because it is highly reactive to thiol groups in proteins, causing them to break down.

Question 18

How is Lithium (Li) used in drugs?

Answer 18

it treats manic depression

Question 19

How is Platinum (Pt) used in drugs?

Answer 19

It is part of Cytotoxic anticancer drugs like cisplatin, carboplatin and oxaliplatin.

Question 20

How is Gold (Au) used in drugs?

Answer 20

its is part of an anti-arthritic drug called Auranofin

Question 21

How is Technetium (Tc) used in drugs?

Answer 21

Tc-99m is a gamma ray emitter which is easy to detect (m stands for metastable) it has a short physical and biological half life so it is not as dangerous as other radioactive substances. One such drug is Cardiolyte, a heart imaging agent.

Question 22

How is Gadolinium (Gd) used in drugs?

Answer 22

It is an MRI relaxation reagent used to enhance image quality.

Question 23

How is Vanadium (V) used in drugs?

Answer 23

it is an Insulin-mimetic compound.

Question 24

How does cisplatin and its more selective cousin carboplatin fight cancer?

Answer 24

pg 4

Question 25

What are the characteristics of a hard acid - hard base ionic interaction?

Answer 25

p-orbital of ligand is filled d-orbital of metal is empty big differences in electronegativity no pi-electron transfer

Question 26

What are the characteristics of a soft acid - soft base chemical bond?

Answer 26

p-orbital of ligand is empty d-orbital of metal is loosely filled small differences in electronegativity pi-electron transfer

Question 27

What are examples of hard metals?

Answer 27

Na + K + Fe 3+ Mg 2+ Ca 2+

Question 28

What are examples of borderline metals?

Answer 28

Fe 2+ Zn 2+ Co 2+ Cu 2+

Question 29

What are examples of soft metals?

Answer 29

Cu + Pt 2+ Hg 2+ Cd 2+ Pb 2+

Question 30

What are the 9 amino acids which can bind metals / metal ions?

Answer 30

Asn Asp Cys Gln His Met Ser, Thr, Tyr

Question 31

Metallothionein: What is the function? Does it bind soft or hard metals? What ligands does it use?

Answer 31

It detoxifies body of heavy metals such as cadmium, lead, and mercury. It is also involved in the metabolism of ZINC and copper. It binds soft metals. The ligand is Cys

Question 32

Calmodulin Function? Type of metal it binds? What ligands does it use?

Answer 32

It acts as an intermediary protein which controls calcium levels, especially in smooth muscle. Hard metal (Ca 2+) Asp, Asn, Glu, H2O

Question 33

Draw monodentate, bidentate and bidentate bridging

Answer 33

pg 3

Question 34

What is the coordination geometry of: 1) cisplatin-Pt2+ / albumin 2) Zn 2+ 3) Cu 2+ prion 4) Fe 3+/Mg 2+ 5) Ca2+

Answer 34

1) Trigonal planar 2) Tetrahedral 3) Square pyramidal 4) Octahedral 5) Pentagonal bipyramidal

Question 35

Transferrin Function? Type of metal it binds What ligands does it use?

Answer 35

It acts as a reservoir and transports iron through the blood stream to the liver, spleen, bone marrow and other areas of the body. It binds Fe 3+ strongly since it has 6 hard oxygen ligands, but has a lower affinity for borderline Fe 2+.

Question 36

What is the coordination geometry of an EF-hand Ca 2+ binding site?

Answer 36

octahedral. (6 side or main chain oxygens, 1 water molecule oxygen)