BIOL213 Lecture Notes - Lecture 2: N-Terminus, Protein Structure, Protein Folding
Lecture 2 – Protein Structure
Lecture outline:
1. The peptide bond
2. Four levels of protein structure
3. Classes of proteins: fibrous versus globular
4. Importance of correct “folding”
Proteins may contain one or more polypeptide chains and may also contain cofactors
(metal ions or organ molecules); prosthetic groups (covalently attached cofactors) another
modifications.
Polypeptide size and numbers vary greatly among proteins. Eg. The human protein has
2,993,000 amino acids in one protein.
Formation of peptide bonds: covalent bond that forms through a dehydration reaction
between two amino acids - condensation reaction that produces water.
Numbering and naming: numbering starts from the amino terminus (the amino end) using
the three-letter code abbreviation of the single letter code.
Structure of proteins: protein molecules adopt a unique 3D shape called a native
conformation. A protein must be converted from a linear chain of amino acids to a
specific 3D information to gain tis function (ie become a mature folded/native protein). A
protein is in its native conformation when it is in its functional, folded state.
The native fold has a large number of favourable interactions within the protein -
multiple weak (non covalent bonds); non-peptide covalent. These help provide stability.
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Document Summary
Lecture outline: the peptide bond, four levels of protein structure, classes of proteins: fibrous versus globular, importance of correct folding . Proteins may contain one or more polypeptide chains and may also contain cofactors (metal ions or organ molecules); prosthetic groups (covalently attached cofactors) another modifications. Polypeptide size and numbers vary greatly among proteins. Formation of peptide bonds: covalent bond that forms through a dehydration reaction between two amino acids - condensation reaction that produces water. Numbering and naming: numbering starts from the amino terminus (the amino end) using the three-letter code abbreviation of the single letter code. Structure of proteins: protein molecules adopt a unique 3d shape called a native conformation. A protein must be converted from a linear chain of amino acids to a specific 3d information to gain tis function (ie become a mature folded/native protein). A protein is in its native conformation when it is in its functional, folded state.
