< Return to Video

A new type of medicine, custom-made with tiny proteins

  • 0:01 - 0:03
    I'm a protein designer.
  • 0:05 - 0:08
    And I'd like to discuss
    a new type of medicine.
  • 0:08 - 0:12
    It's made from a molecule
    called a constrained peptide.
  • 0:12 - 0:15
    There are only a few constrained
    peptide drugs available today,
  • 0:15 - 0:18
    but there are a lot that will hit
    the market in the coming decade.
  • 0:18 - 0:21
    Let's explore what these new
    medicines are made of,
  • 0:21 - 0:24
    how they're different and what's causing
    this incoming tidal wave
  • 0:24 - 0:25
    of new and exciting medicines.
  • 0:26 - 0:30
    Constrained peptides
    are very small proteins.
  • 0:30 - 0:34
    They've got extra chemical bonds
    that constrain the shape of the molecule,
  • 0:34 - 0:36
    and this makes them incredibly stable
  • 0:36 - 0:37
    as well as highly potent.
  • 0:38 - 0:42
    They're naturally occurring,
    our bodies actually produce a few of these
  • 0:42 - 0:44
    that help us to combat
    bacterial, fungal and viral infections.
  • 0:44 - 0:46
    And animals like snakes and scorpions
  • 0:46 - 0:49
    use constrained peptides in their venom.
  • 0:49 - 0:52
    Drugs that are made of protein
    are called biologic drugs.
  • 0:52 - 0:54
    So this includes constrained peptides,
  • 0:54 - 0:56
    as well as medicines like insulin
  • 0:56 - 1:00
    or antibody drugs like Humira or Enbrel.
  • 1:00 - 1:03
    And in general, biologics are great
  • 1:03 - 1:07
    because they avoid several ways
    that drugs can cause side effects.
  • 1:07 - 1:09
    First, protein.
  • 1:09 - 1:12
    It's a totally natural,
    nontoxic material in our bodies.
  • 1:12 - 1:15
    Our cells produce tens of thousands
    of different proteins,
  • 1:15 - 1:17
    and basically all of our food
    has protein in it.
  • 1:17 - 1:21
    And second, sometimes drugs interact
    with molecules in your body
  • 1:21 - 1:23
    that you don't want them to.
  • 1:23 - 1:25
    Compared to small molecule drugs,
  • 1:25 - 1:27
    and by this I mean
    regular drugs, like aspirin,
  • 1:27 - 1:29
    biologics are quite large.
  • 1:29 - 1:33
    Molecules interact when they adopt shapes
    that fit together perfectly.
  • 1:33 - 1:35
    Much like a lock and key.
  • 1:35 - 1:37
    Well, a larger key has more grooves,
  • 1:37 - 1:40
    so it's more likely to fit
    into a single lock.
  • 1:40 - 1:43
    But most biologics also have a flaw.
  • 1:43 - 1:44
    They're fragile.
  • 1:44 - 1:46
    So they're usually
    administered by injection,
  • 1:46 - 1:49
    because our stomach acid
    would destroy the medicine
  • 1:49 - 1:50
    if we tried to swallow it.
  • 1:50 - 1:52
    Constrained peptides are the opposite.
  • 1:52 - 1:54
    They're really durable,
    like regular drugs.
  • 1:54 - 1:59
    So it's possible to administer them
    using pills, inhalers, ointments.
  • 2:00 - 2:04
    This is what makes constrained peptides
    so desirable for drug development.
  • 2:04 - 2:06
    They combine some of the best features
  • 2:06 - 2:10
    of small-molecule
    and biologic drugs into one.
  • 2:10 - 2:12
    But unfortunately,
    it's incredibly difficult
  • 2:12 - 2:15
    to reengineer the constrained peptides
    that we find in nature
  • 2:15 - 2:17
    to become new drugs.
  • 2:17 - 2:18
    So this is where I come in.
  • 2:18 - 2:22
    Creating a new drug
    is a lot like crafting a key
  • 2:22 - 2:24
    to fit a particular lock.
  • 2:24 - 2:26
    We need to get the shape just right.
  • 2:26 - 2:29
    But if we change the shape
    of a constrained peptide by too much,
  • 2:29 - 2:31
    those extra chemical bonds
    are unable to form
  • 2:31 - 2:33
    and the whole molecule falls apart.
  • 2:33 - 2:37
    So we needed to figure out
    how to gain control over their shape.
  • 2:37 - 2:39
    I was part of a collaborative
    scientific effort
  • 2:39 - 2:42
    that spanned a dozen institutions
    across three continents
  • 2:42 - 2:45
    that came together
    and solved this problem.
  • 2:45 - 2:49
    We took a radically different approach
    from previous efforts.
  • 2:49 - 2:51
    Instead of making changes
    to the constrained peptides
  • 2:51 - 2:52
    that we find in nature,
  • 2:52 - 2:56
    we figured out how to build new ones
    totally from scratch.
  • 2:56 - 2:57
    To help us do this,
  • 2:57 - 3:00
    we developed freely available
    open-source peptide-design software
  • 3:00 - 3:02
    that anyone can use to do this, too.
  • 3:02 - 3:03
    To test our method out,
  • 3:03 - 3:06
    we generated a series
    of constrained peptides
  • 3:06 - 3:08
    that have a wide variety
    of different shapes.
  • 3:08 - 3:11
    Many of these had never been seen
    in nature before.
  • 3:11 - 3:14
    Then we went into the laboratory
    and produced these peptides.
  • 3:14 - 3:16
    Next, we determined
    their molecular structures,
  • 3:16 - 3:18
    using experiments.
  • 3:18 - 3:20
    When we compared our designed models
  • 3:20 - 3:21
    with the real molecular structures,
  • 3:22 - 3:25
    we found that our software
    can position individual atoms
  • 3:25 - 3:28
    with an accuracy that's at the limit
    of what's possible to measure.
  • 3:28 - 3:30
    Three years ago, this couldn't be done.
  • 3:30 - 3:33
    But today, we have the ability
    to create designer peptides
  • 3:33 - 3:37
    with shapes that are custom-tailored
    for drug development.
  • 3:37 - 3:38
    So where is this technology taking us?
  • 3:39 - 3:41
    Well, recently,
  • 3:41 - 3:43
    my colleagues and I
    designed constrained peptides
  • 3:43 - 3:46
    that neutralize influenza virus,
  • 3:46 - 3:49
    protect against botulism poisoning
  • 3:49 - 3:51
    and block cancer cells from growing.
  • 3:51 - 3:53
    Some of these new drugs
  • 3:53 - 3:56
    have been tested in preclinical trials
    with laboratory animals.
  • 3:56 - 4:00
    And so far, they're all safe
    and highly effective.
  • 4:00 - 4:03
    Constrained peptide design
    is a cutting-edge technology,
  • 4:03 - 4:06
    and the drug development pipeline
    is slow and cautious.
  • 4:06 - 4:08
    So we're still three to five years
    out from human trials.
  • 4:08 - 4:10
    But during that time,
  • 4:10 - 4:11
    more constrained peptide drugs
  • 4:11 - 4:14
    are going to be entering
    the drug development pipeline.
  • 4:14 - 4:18
    And ultimately, I believe
    that designed peptide drugs
  • 4:18 - 4:20
    are going to enable us all to break free
  • 4:20 - 4:23
    from the constraints of our diseases.
  • 4:23 - 4:24
    Thank you.
  • 4:24 - 4:28
    (Applause)
Title:
A new type of medicine, custom-made with tiny proteins
Speaker:
Christopher Bahl
Description:

more » « less
Video Language:
English
Team:
closed TED
Project:
TEDTalks
Duration:
04:41

English subtitles

Revisions Compare revisions