The Wonderful World of Proteins

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The Wonderful World of Proteins

• Amino Acids
• Polypeptides
• Elements of protein structure.
• Forces that assemble proteins.
• Protein secondary structures

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When you think Protein
When I think Protein
Big structures and little machines.
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Proteins Run the Whole Show.

• Proteins are the gears, motors, and machines of
  life. Just a few roles of proteins
• Biological Catalysis Enzymes catalyze chemical
  reactions with extreme specificity. Proteins have
  a hand in the synthesis of every molecule in a
  living organism (including other proteins).
• Storage Some proteins keep reactive or toxic
  molecules in a safe storage container.
• Eg. Hemoglobin, Ferritin.

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Proteins Run the Whole Show.

• DNA is the head, proteins are the hands
• Regulation Proteins are the conductors of the
  complicated orchestration of cellular processes.
• Antibodies Proteins form the basis for the
  immune response in higher eukaryotes.
• Structure Hair, claws, tendons, skin - its all
  made of protein.

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Protein is yet another polymer.

• Where DNA and RNA have four bases each, proteins
  are a linear sequence of 20 amino acids.

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The Amino Acids
Maybe youve seen these guys before, but your
gonna see them again!
Amine, Carbon, and Carboxylate - In solution is
always a Zwitterion.
The Carboxyl (Deprotonated)
The Amine (With 3 Hs)
The R group Alanine - R CH3
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There are 20 of them to play with!
Twenty - Thats a two and a zero - Seems like a
lot, but you can group them by their
personalities
The greasy hydrophobic residues. (I call Rs
residues)
Makes me Sleepy
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Thats two hands and two feet of amino acid fun!
The Polar Residues
The Charged Residues
Thing of all the neat things you could make
mixing together these twenty amino acids in a
linear polymer!
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Proteins are made of amino acids linked by
peptide bonds.
The amine of one amino acid is linked to the
carboxyl of another into an amide bond through
condensation. This bond is also called a peptide
bond.
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The Cornucopia of Proteins
A huge number of unique proteins can be made by
linking together different sequences of amino
acids in specific orders.
The N-terminus
The C-terminus
A four residue polypeptide
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Each unique sequence makes a unique protein with
unique functions.
Usually proteins are made of between 100 - 2000
amino acids per polypeptide.
-Leu - Arg - Asp - Asp - Ser - Leu - Ala - Asp -
Glu - Leu - Tyr - Phe - Glu -
The sequence of each protein is encoded in the
DNA of the organisms genome. Thus the genome of
an organism defines the structures of the gears
and motors of the cell.
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Flow of Genetic Information
DNA
RNA Transcription
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Heres the magic partPolypeptides fold up into
compact and complicated 3-D structures.
Protein Folding
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Structure Begets Function.

• The 3-D structure of macromolecules form
  molecular structures and machines that perform
  the functions of life.

HIV infecting T-cells HIV gp120/ CD4 complex
DNA polymerase Replicate DNA
Rhodopsin Sense light
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Structure Function
This DNA polymerase is shaped just right to grab
a DNA helix and replicate one strand from the
other.