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Trace elements: As precious as gold for your health

Dominic Hare and Blaine Roberts UTS Science in Focus Public Lecture 22 August 2012

UTS: Centre for Forensic Science

First of all, thanks to…

UTS: Centre for Forensic Science

Atoms: Building blocks of the Universe

• The atoms that make up your body, your house, your

brand new car are as old as the universe itself

– 14 or so billion years, give or take a few leap years

• How atoms interact with each other determines how

matter changes

• Consider then, that the atoms in your body have

experienced an eternity of life experiences, sights, smells, sounds, loves, despairs stretching all the way back to the birth of the cosmos.

UTS: Centre for Forensic Science

UTS: Centre for Forensic Science

Chemical properties of atoms

• The number of protons determines which element the

atom represents

– Hydrogen has 1, helium has 2, lithium has 3…

• The number of neutrons determines which isotope of

the element it represents

– Isotopes have the same properties, but have a slightly different mass

• The number of electrons orbiting the nucleus

determines how the atom will react

UTS: Centre for Forensic Science

Electrons and chemical reactions

• How electrons interact with other atoms determines

what state an atom exists in, and how they react

UTS: Centre for Forensic Science

What makes you, you

UTS: Centre for Forensic Science

What about the rest?

• 0.1% sulfur, potassium, sodium and chlorine
• 0.006% iron, or 4.2 grams, equivalent to everyone

here relative to Sydney’s population

• 0.0001% copper, or 0.072 grams, equivalent to a

single grain of rice in 5 buckets of water

• 0.000016% iodine, or 0.02 grams, equivalent to one

minute every 6 years

• 0.0000021% cobalt, or 0.000003 grams, equivalent to
• ne drop of water in an Olympic-sized swimming pool

UTS: Centre for Forensic Science

So, how can we possibly measure something that small?

UTS: Centre for Forensic Science Sodium Potassium Copper

Flame tests

UTS: Centre for Forensic Science

Atomic emission

• As the sample heats in the flame, it gets broken down

into it’s constituents

• Electrons moving around the nucleus take in some of

the energy from the flame and jump up to a higher

• rbital
• When these electrons lose energy, they drop back

down to their original orbital, emitting light as they go

UTS: Centre for Forensic Science

Atomic emission spectra

Iron Hydrogen Mercury

UTS: Centre for Forensic Science

Emission is great, but…

• It often lacks the sensitivity to measure truly trace

amounts of something

• How can we measure atoms directly?

UTS: Centre for Forensic Science

On a lighter note…

• Everything weighs something (or, at least officially

since July 4, 2012)

• Each and every proton and neutron (and even

electron) contributes to an element’s mass

• If phosphorus has 15 protons…
• …and sulfur has 16 protons…
• …an atom of sulfur must weigh

more than an atom of phosphorus!

UTS: Centre for Forensic Science

The ICP: A super-charged Bunsen burner

UTS: Centre for Forensic Science

The evolution of the ICP-MS

Inductively coupled plasma-mass spectrometers circa 1980s

UTS: Centre for Forensic Science

You were talking about the body…?

• An ICP-MS gives us a technique that is sensitive

enough to be able to measure those minute differences in trace elements in the body

• Cutting-edge ICP-MS is capable of detecting down to

parts-per-quadrillion, or one centimetre in 50 round trips to the Sun

UTS: Centre for Forensic Science

Laser ablation

UTS: Centre for Forensic Science

LA-ICP-MS Imaging

UTS: Centre for Forensic Science

Imaging Process

UTS: Centre for Forensic Science

Imaging Process

ICP

Cones

Ion lenses

Mass Spec

Ion Detector

Data Processing

UTS: Centre for Forensic Science

LA-ICP-MS imaging

• Each image gives us quantitative spatial information

about trace elements, without the need for excision

1mm Iron

UTS: Centre for Forensic Science

LA-ICP-MS imaging

• We can look at how diseases change trace elements at

the micro-meter scale, in situ.

Iron 1mm

UTS: Centre for Forensic Science

Reconstructing iron in the mouse brain

UTS: Centre for Forensic Science

Three-dimensional imaging

UTS: Centre for Forensic Science

Where are we going now?

Trace elements: As precious as gold for your health

Dominic Hare and Blaine Roberts UTS Science in Focus Public Lecture 22 August 2012

Periodic Table

Abundance in the Universe

What are the Biological Elements of Life?

Lipids Protein Carbohydrates DNA

Central Dogma of Biology

Lipids = membranes Carbohydrates = energy Proteins = function

Proteins equal Function

“Pretty much anything a cell does, a protein does it.”

–P. Andrew Karplus

3D crystal structure of antioxidant enzyme Cu, Zn Superoxide Dismutase

Human Genome

• 23 chromosomes ~ 22,000 genes
• 30-50% of proteins use metal to function

Examples; Hemoglobin(Fe), Ferritin (Fe), Matrix metalloprotease (Zn), Xanthine Oxidase (Mo) ….etc.

Vitamin and mineral Supplements

*Daily value not established We know that many minerals are essential but don’t know how much, why in most cases.

Diseases caused by mineral Deficiency

Hemochromotosis Anemia (Fe, Cu) Acrodermatitis enteropahtica (Zn)

Menke’s disease (Cu) Wilson’s disease (Fe)

Malnutrition

Zinc deficiency one of the most common deficiencies in the world Over 2 Billion people are estimated to be deficient in zinc.

• Decreased wound healing
• Impaired immune function
• Impaired growth and neurological

development

• Aggressive behavior

Alzheimer’s disease

• Although named after Alois the disease was describe previously by

Fischer, Bonfiglio, Perusini.

• Accounts for 50-80% of dementia.
• Average patient lives 8 years but can be up to 20 years.
• Projected cost of $20 Trillion dollars over the next 40 years.

Alois Alzheimer Auguste Deter

Alzheimer’s Pathology

Amyloid Plaques

• Pathology begins 10-15 years before disease

symptoms arise (Braak 1996)

• Disease pathology begins in the neocortex and

and progressively spreads through the cortex.

• Massive neuronal loss >50%.

Fe, Cu, K, and Rb are altered in AD Brain.

Amyotrophic Lateral Sclerosis

Zinc-deficient SOD hypothesis for ALS

• Zinc deficient SOD hypothesis

– Without zinc, copper is reduced ~3000x faster than Cu,Zn-SOD (Estevez,

AG et al.) – Many SOD mutants have a reduced affinity for zinc (Crow, JP et al.)

Estevez, A. G., Crow, J. P., Sampson, J. B., Reiter, C., Zhuang, Y., Richardson, G. J., Tarpey, M. M., Barbeito, L. & Beckman, J. S. (1999). Induction

• f nitric oxide-dependent apoptosis in motor neurons by zinc-deficient superoxide dismutase. Science 286, 2498-500.

Crow, J. P., Sampson, J. B., Zhuang, Y., Thompson, J. A. & Beckman, J. S. (1997). Decreased zinc affinity of amyotrophic lateral sclerosis-associated superoxide dismutase mutants leads to enhanced catalysis of tyrosine nitration by peroxynitrite. J Neurochem 69, 1936-44.

e-

Ascorbate

O=O O=O•- + NO• ONOO-

Cu+2 Cu+2

Cu+1 Cu+1

Apoptosis

Cu,Zn Zinc- deficient Purified SOD

Measuring Global Metalloprotein Changes with Liquid Chromatography-ICPMS

Size exclusion column (Agilent BioSEC 4.6x300mm)

Output Vo Vt

Decreasing MW

Agilent HPLC 1200 Agilent 7700 ICP-MS

Measure Protein Metal Status Directly

Vit B12 Thyroglobulin, 660kDa Thyroglobuli n aggregate Ferritin , 440kD a Cu,Zn- SOD, 32kDa Catalas e, 256kDa V t Conalbumi n, 75kDa

Metalloproteomics = measure of metal bound to protein

Application of Metalloproteomics

The Zn metalloproteome Each island is a different Zn-Protein

Micronutrient Information Center

For more information on minerals and vitamins in health and disease please visit the Linus Pauling Institute Micronutrient Information Center. (http://lpi.oregonstate.edu/)

Summary

• Proteins are important for cellular function
• Metals are important for protein function
• Deficiencies in minerals can manifest in many ways
• Little is know about the role of minerals in disease
• Metalloproteins play pivotal roles in normal cellular

function and in disease pathologies.