Tertiary structure
This presentation is the property of its rightful owner.
Sponsored Links
1 / 20

Tertiary Structure PowerPoint PPT Presentation


  • 90 Views
  • Uploaded on
  • Presentation posted in: General

Tertiary Structure. A result of interactions between side (R) chains that are widely separated within the peptide chain Covalent disulfide bonds - between 2 cysteine AA Salt bridges - between AA w/ charged side chains (acid & base AA) Hydrogen bonds - between AA with polar R groups

Download Presentation

Tertiary Structure

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Tertiary structure

Tertiary Structure

  • A result of interactions between side (R) chains that are widely separated within the peptide chain

    Covalent disulfide bonds - between 2 cysteine AA

    Salt bridges - between AA w/ charged side chains

    (acid & base AA)

    Hydrogen bonds - between AA with polar R groups

    Hydrophobic attractions - between NP side chains

  • Spatial relationship of 2˚ structures

  • Level responsible for 3-D orientation of proteins.

  • Thermodynamically most stable conformation of a protein.

  • May have intra-chain and inter-chain linkages


Tertiary structure

Tertiary protein structure bonding


Tertiary structure

Human insulin, a small two-chain protein: Tertiary structure has both intra-chain & inter-chaindisulfide linkages.


Tertiary structure

3o protein structure - Non-covalentR group interactions:

(a) electrostatic interaction

(b) hydrogen bonding

(c) hydrophobic interaction


Tertiary structure of the single chain protein myoglobin

Tertiary structure of the single-chain protein: myoglobin.

found mainly in

muscle tissue

where it serves

as an intracellular

storage site

for oxygen


Tertiary structure

  • Quaternary structure:

  • Shape or structure from joining more than one protein molecule (protein subunits) together to make a larger protein complex.

  • Same non-covalent bonds as tertiary form:

  • Electrostatic interactions (Van der Waals)

  • Hydrophobic interactions

  • Hydrogen bonding

  • Quaternary structure is easily disrupted


Tertiary and quaternary structure of the oxygen carrying protein hemoglobin

Tertiary and quaternary structure of the oxygen-carrying protein hemoglobin.

When O2 binds to

Fe of Heme group,

tension on the

molecule pulls

an amino acid,

which alters the

3o structure –

This in turn affects the 4o structure bonds Exposes more heme sites -

creates greater affinity for O2


Protein structure r eview

Protein StructureR eview


Tertiary structure

  • Review part 1: can you…

  • List the characteristics of proteins

  • Draw the basic structure of amino acids (a.a.)

  • Compare & contrast structural differences

  • between the 4 main classes of a.a.

  • Draw a peptide formation between a.a.

  • List characteristics of four levels of protein

  • structure (1o, 2o, 3o, and 4o)


Types of proteins

Types of Proteins

Two major types - based on structural levels

Fibrous - peptide chains are arranged in long strands/sheets

Globular - peptide chains are folded into spherical/globular shapes


Tertiary structure

Fibrous versus Globular protein

Fibrous Proteins

Have fiber-like structures – good structural material. Relatively insoluble in water.

Unaffected by moderate in temp and pH.

Subgroups within this category include:

Collagens & Elastins: the proteins of connective tissues. tendons and ligaments.

Keratins: proteins that are major components of

skin, hair, feathers and horn.

Fibrin: a protein formed when blood clots.

Myosin: a protein that makes up muscle tissue


Tertiary structure

Globular Proteins

In living organisms:

Serve regulatory, maintenance and catalytic roles.

Include hormones, antibodies, and enzymes.

Either dissolve or form colloidal suspensions in water.

Generally more sensitive to temperature & pH change

than fibrous protein counterparts.

Examples within this category include:

InsulinRegulatory – controls glucose levels

HemoglobinTransport – moves O2 around body

MyoglobinStorage – stores O2 near muscles

TransferrinTransport – moves Fe in blood

ImmunoglobulinsDefense – attacks invading pathogens


Fibrous structural protein keratin

Fibrous structural protein:Keratin

Nails Horn & Hoof feathers Hair

Keratin structural molecules are normally long and thin,

insoluble in water, very high tensile strength,and arranged to form fibers.

Composed of long rods, twisted together,

laid down in criss-cross matrix form.


Tertiary structure

Keratinized stratified squamous epithelial layer:

found only in skin!

Dead cell layers at surface.  Keratin effectively waterproofs cells. Blocks diffusion of nutrients & wastes.

Provides protection against  friction, microbial invasion, and desiccation.


Tertiary structure

Many cross-links create very little flexibility: horns, claws, hooves, or nails.

Fewer cross-links allows some stretching but returns to normal: wool, skin, and muscle proteins.


Tertiary structure

Fibrous structural protein: Collagen

  • Collagen most abundant protein in human body

  • Structural protein

  • Major component of the connective tissue:

  • sheaths muscles & attaches them to bone through tendons

  • or attaches skeletal elements together through cartilage

Collagen exists as a molecule that is tightly coiled about itself forming a secondary triple coil.


Tertiary structure

The molecules bunch together in groups of three,

forming a larger coil (superhelical coil)

that gives collagen fibers their strength in living tissue.

Tendons


Tertiary structure

Collagen structure can be disrupted

in diseases such as scurvy,

which is a lack of ascorbic acid, a cofactor

in the hydroxylation of proline (Hydroxyproline)

In addition, collagen structure is disrupted

in rheumatoid arthritis.


Myosin actin

Myosin & Actin

  • Muscle proteins which allow for contraction of the muscle.

  • Myosin

    • Fibrous tail - two coiled -helices

    • Globular head - one at the end of each tail

  • Actin

    • A multimeric protein

    • Long fiber of connected globular proteins


Tertiary structure

Muscle tissue contracts

and relaxes when

triggered by electrical

stimuli from brain.

Muscle fibers bundled

together make up a

single muscle. Many

myofibrils make up

each fiber.

Myofibrils have

striations, formed by

arrangements of

protein molecules.

The protein forms filaments. 2 types of filament: thick & thin.

Thick filaments contain myosin; thin filaments contain

actin, troponin and tropomyosin.


  • Login