Bio-inorganic Chemistry

Vakinformatie

Nieuw vak sinds 2013-2014. Het vak wordt gedoceerd door Prof. Tatjana Vogt en behandelt verschillende aspecten van de bioanorganische chemie, gaande van de functie van metalen in enzymen, mogelijke onderzoeksmethoden tot medicinale toepassingen. Lessen in het Engels. Met een taak die op 8 van de 20 punten staat.

Examenvragen

12 jan 2018

1. (4p) Fe(III) is transported through the body via transferrin, a Fe(III) protein.
   1. Which anion is important to bind Fe(III)? (= bicarbonaat)
   2. What structural changes/molecular forms are induced when Fe(III) is bound to transferrin.
   3. What experiment can be used to distinguish the different molecular forms of transferrin?
   4. Does it bind only Fe(III) or could other metals also bind?
2. (3p) Two 1HNMR spectra are given. One is of oxidized myoglobin and the other is of deoxidized myoglobin. Which spectra belongs to the oxidized and wich to the deoxidized form? Explain why.

Gegeven: Structuur van Fe in de ring + twee spectra met serieuze pieken en daarbij telkens ook een spectra van de protonen van bèta corrin, eentje niets te zien de andere twee pieken. Eén spectra was niets te zien van de protonen van bèta corrin & de andere vertoonde twee pieken rond 50 ppm. De reden dat 02-bound myoglobin diamagnetic is omwille van binding met zuurstof. Unbound myoglobin is paramagnetic en zal dus upfield shifts veroorzaken in het NMR spectrum.

1. (3p) Alkaline en purple acid phosphatase
   1. Fill in missing metals, reaction products and transition states
   2. What is the main difference in active site between purple acid phosphatase and alkaline phosphatase. Do they work at same conditions?
   • Bijvraag: wat gebeurt er bij een heel lage pH bij purple acid phosphatase (= anders wordt ook OH aan ijzer ook geprotoneerd en is er geen nucleofiele aanval op fosfaat)
2. (2p)
   • What makes 99mTc highly suitable for single photon emission computed tomography (SPECT)?
   • How is this isotope being produced in a clinical environment?

01 sep 2017

1. (3p)
   • How are copper sites classified?
   • Which technique is used to study them, what results do you get from it?
   • Why does this technique not work for type III?
2. (3p) Given is part of the reaction mechanism of purple acid phosphatase (voorbeeld examen)
   • Fill in the missing metal centers, transition state and reaction products
   • What is the main difference between the active site of purple acid phosphatase and alkaline phophatase?
   • Can both enzymes be used under the same conditions?
3. (3p)
   • Draw and explain the 2 different electronic configurations of Rebredoxins.
   • Which spectroscopic techniques can be used to distinguish these 2 states?
   • Why are both state in high spin?
4. (3p)
   • Discuss the 4 bindingspots of Human Serum Albumine.
   • Where and why would Hg(II) bind?

30 jan 2017

1. • Advantages of coordination compound based dyes for optical imaging.
   • Most common metals for this method and why
2. • Axial groups on methylmalonyl CoA mutase
   • which reaction is catalysed by this enzym
   • Explain the first step of this reaction mechanism and what is the oxidation state(s) of Co
3. -> 2 Mossbauer spectra gegeven
   • 2 most important limits of 57Fe Mossbauer spectroscopie
   • Which parameters can be derivate from the spectra
   • Which of the 2 has the most symmetry and explain why
4. • 2 subunits of ferritin + explain proportion difference in different tissues between the 2 subunits
   • Most important difference between the 2 subunits

26 jan 2017

1. What are metallothioneines? Which metals are associated and why does it bind so many metals?
2. Why is Gd a good metal for MRI enhancement? What's the problem with Gd and how is this solved?
3. P450: In which reaction is it involved? Draw remaining intermediates (4,5,6). Why is NADPH used? How many electrons are participating?
4. Describe binding of oxygen to hemoglobin. How is this related to cooperative binding? How is the binding regulated?

10 jan 2017

1. (2p)
   • What makes 99mTc highly suitable for single photon emission computed tomography (SPECT)?
   • How is this isotope being produced in a clinical environment?
2. (3p)
   • Which metal is found in the active sit of hemerythrin?
   • How does oxygen Bind to it?
   • Explain the oxidation states present in oxy and in deoxy form of hemeryhtrin. Which technique iq best suitable to study this and why?
3. (4p) Given is part of the reaction mechanism of purple acid phosphatase (voorbeeld examen)
   • Fill in the missing metal centers, transition state and reaction products
   • What is the main difference between the active site of purple acid phosphatase and alkaline phophataseµ? Can both enzymes be used under the same conditions?
4. (3p)
   • What are the different electron carrying components in complex III from the mitochondrial respiration?
   • explain how electrons are being transported to cytochrome c.

25 jan 2016

1. ^99mTc: properties that make it useful for SPECT, production in clinical environment
2. Reaction mechanism of aconitase
3. Rubredoxin: elektronenconfiguratie en hoe de twee vormen via spectroscopische techniek onderscheiden
4. Welke elektronencarriers zijn er in Complex III en hoe wordt cytochroom C hier gereduceerd?

21 jan 2016

1. Bespreek humaan serum albumine, 4 bindingsplaatsen. Waar en waarom zou Hg(II) binden
2. Exact de vraag van het voorbeeldexamen op toledo ivm alkaline en purple acid phosphatase (reactieschema aanvullen en het verschil uitleggen)
3. Nitrogenase uitleggen, welke delen voor wat dienen, reactievergelijking geven
4. Hemerythrin, oxidatie dingen uitleggen, techniek om dit te bestuderen.

22 jan 2015 (nm)

1. How are copper sites classified? Which technique is used to study them, what results do you get from it? Why does this technique not work for type III
2. Which factors regulate O2 binding to hemoglobin? And how?
3. Fill in the missing reactant and reaction products (Dimethyl sulfoxide reductase), what are the oxidation states of Mo? Draw the overall chemical reaction. Where do the 2 electrons come from?
4. Give two examples of Platinum anti-tumor drugs with better efficacy

23 jan 2014 (vm)

1. Give four mechanisms by which cells can become resistant to cisplatin. How can you circumvent these resistance mechanisms? (4p)
2. Reaction mechanism of aconitase: (6p)
   • fill in the missing reactants and reaction products.
   • Identify the three main reactions in this mechanisms.
   • Why is the step indicated with A so important? (A was the 180° flip)
   • In which pathway does this enzyme play an important role within the cell?
3. Explain in detail the electronic states of Fe in the oxy and deoxy states of myoglobin. Which technique is best to differentiate between these two states? (4p)
4. Which electron carriers play a role in complex III of the mitochondrial respiration pathway? How do electrons reach cytochrome c? (6p)

15 jan 2014 (vm)

1. Why is Gd a good metal for MRI? What are the disadvantages? How are these problems being attacked? (4p)
2. Which reaction is catalysed by methylmalonyl-CoA mutase? Describe the first reaction step? (6p)
3. Two Mossbauer spectra were given from two different di-iron species(6p)
   • What do you need in order to obtain these Fe Mossbauer spectra?
   • What parameters can you derive from these graphs?
   • Which is more symmetric and why?
4. What function do metallothioneines have? What metals and aminoacids are associated with them? Are they specific for certain metals? (4p)

15 jan 2014 (nm)

1. properties that make it useful for SPECT, production in clinical environment (4p)
2. Reaction mechanism of purple acid phosphatase (6p)
   • Fill in missing metals, reaction products and transition states
   • What is the main difference in active site between purple acid phosphatase and alkaline phosphatase. Do they work at same conditions?
3. Explain the electronic structure of Fe in oxidized and reduced [2Fe-2S] ferredoxins. Which two spectroscopic methods can be used to distinguish between them and why? (5p)
4. What is the major consequence of O binding to the structure of hemoglobine? How is this related to cooperative binding? (5p)