DCE SMART Team 2012-2013

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An Investigation in Bee Venom

Background

What is SMART Team?

• S - students
• M - modeling
• A
• R - research
• T - topic

SMART Team 2012-2013

• This is a team related program where we develop teamwork skills and we work closely to understand and model the structure of proteins.
• This year we are working to understand the physiological response to a bee sting in humans.

How do we do this?

• Readings (primary citations and popular literature)
• More reading(online sources)
• Jmol(A program that helps model a 3-D picture of a molecule)

Our Task as a Remote SMART Team

Interpreting Sources:

The Hard Part

JMOL

X-Ray Crystallography

• Method to determine the atomic and molecular structure
• Crystalline atoms diffract X-rays in specific directions
• The diffracted rays are projected
• A crystallographer can create a 3D image and determine the (X,Y,Z) coordinates for each atom and their chemical bonds.

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http://fineartamerica.com/featured/early-image-of-dna-omikron-and-photo-researchers.html

Protein Data Bank

Bee Venom

What is it and why is this important?

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General Bee Facts

• About two million people in the United States are allergic to bee stings
• In the most severe cases, an allergic reaction to a bee sting can cause anaphylactic shock, requiring treatment with a shot of epinephrine
• About 100 Americans die every year from bee stings

The Adverse Reactions To Bees

• Pain and itching
• Anaphylactic shock-a life threatening allergic reaction

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Components Of Bee Venom

Hyaluronic Acid and

Hyaluronidase

The Extracellular Matrix:

The Simplified Version

Looks like there's a lot of empty room for things to move around in the space between cells

The Extracellular Matrix:

What it Really Looks Like

http://news.medill.northwestern.edu/chicago/news.aspx?id=93005

A tangled mess which prevents the invasion of foreign organisms

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Hyaluronic Acid (HA)

• A polysaccharide comprised of repeating disaccharide units
• Found throughout the ECM connecting protein filaments, collagen fibers, and connective tissue cells
• Acts as a stabilization mechanism, shock absorber, and lubricant for cells

Hyaluronidase:

A Naturally Occurring Regulatory Mechanism

• Involved in physiological and pathological processes from fertilization to aging
• Maintain the balance between the anabolism and catabolism of HA

Hyaluronidase:

A Spreading Factor for Toxins

• Bee venom contains hyaluronidase
• Hyaluronidase is an enzyme that degrades Hyaluronic Acid
• Causes capillary dilation, which allows inflammation to spread

The Molecule of Hyaluronidase

• Strands of HA positioned in the substrate binding groove
• The red spot is the catalytic residue

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Alternating Blue "String:"

Hyaluronic Acid

Green:

Catalytic Residue (glu113)

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Light Blue:

Positioning Residues

Purple:

Positioning Residues Lining the Substrate Binding Groove

Orange:

Sugar Placing Residues

Mechanism of Degradation:

Nucleophilic Substitution

Glutamic

Acid

Hyaluronidase (113)

Catalytic Residue

X

X

Phospholipase

and the

Phospholipid Bilayer

A Cell's Protection:

The Lipid Bilayer

The component of bee venom responsible for the immunological response can't pass through directly because...

The Phospholipase Molecule

The Function of Phospholipase

Hydrolyzes the 2-ester bond of L-glycerophospholipids

http://www.indiana.edu/~oso/Fat/SolidNLiquid.html

http://lipidlibrary.aocs.org/animbio/phospholipases/index.htm

X

Blue:

Catalytic Residues

Green:

Calcium Ion

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Orange:

Calcium Binding Residues

Pink:

Interfacial Binding Surface

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Part of phospholipids, arachidonic acid, when cleaved off by phospholipase, is released and causes an inflammatory cascade.

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It also causes decreased blood pressure and inhibits blood coagulation.

http://lipidlibrary.aocs.org/animbio/phospholipases/index.htm

http://www.dog-in-pain.com/aspirin-and-nsaids/

The Missing Link:

Melittin

Melittin

• Most abundant protein in bee venom

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Blue: polar

Pink: charged

Green: hydrophobic

The Molecule of Melittin

Hydrophobic

Region

Hydrophilic

Hydrophilic

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Because of its structure, it spontaneously integrates into the lipid bilayers and acts as a lytic agent.

The Function of Melittin

• Acts as a stimulator of phospholipase
• Inhibits protein kinase C which
• Increases membrane permeability
• Changes to membrane proteins
• Contributes to cellular destruction

Melittin In Video

Immunological Effects

Melittin and Cortisol

• One of the functions of melittin is to induce the production of cortisol, a steroid-like hormone.
• Cortisol has a tendency to suppress the immune system by inhibiting the growth of T-cells and weakening the signal of Interleukin-1, a regulator of immune and inflammatory response.
• Cortisol, combined with the release of histamine from mast cells, plays a role in the causing of anaphylactic shock.

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http://science.howstuffworks.com/zoology/insects-arachnids/bee2.htm

The Applications of Knowledge

Significance

Beneficial Side of Bees Stings

Apitherapy

• Bees stings, while painful have many benefits
• A field of folk medicine known as Apitherapy
• Includes most bee products, including stings
• Bee stings used to treat:
• MS
• Arthritis
• Lupus
• Autoimmune Diseases

Historical Evidence

• The use of bee products for medical purposes is ancient
• Found in many ancient texts
• Veda
• Bible
• Quran
• Most focused around consumption of bee products and not stings

The Plausibility Of Apitherapy

• Purposed to fight a variety of different medical problems
• Plausibility lies in Melittin

Melittin's Applications

Melittin and HIV

• Kills HIV cells by punching holes through their protective outer layer and prevent infection
• Gel PREVENTS the spread of HIV/AIDS but would NOT CURE it in those who already have it
• As an alternative to anti-HIV drugs that inhibit the virus's ability to replicate

http://news.wustl.edu/news/Pages/25061.aspx

http://www.thesun.co.uk/sol/homepage/news/4831508/Bee-stings-could-prevent-the-spread-of-HIV-doctors-claim.html

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• Nanoparticles with melittin (purple and green) fuse with HIV (small, spikey circles) destroying the virus's protective envelope
• "Molecular Bumpers" (small red ovals) prevent similar destruction of larger body cells

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http://news.wustl.edu/news/Pages/25061.aspx

Melittin and HIV

The End

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Three Bee Venom Proteins Webpage

Acknowledgements

• Dr. Colton
• MSOE SMART Team Program
• MSOE Center for Biomolecular Modeling
• Mr. Heeren