1 / 16

Protein Structure

Protein Structure. FDSC400. Biological?. Food?. Protein Functions. Protein Structure. 20 Amino Acids. Coded in DNA. Primary. Secondary. Self assembly to a single (native) structure. Depends on primary structure and solution conditions. Tertiary. ( ). Quaternary.

amity-ramos
Télécharger la présentation

Protein 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. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Protein Structure FDSC400

  2. Biological? Food? Protein Functions

  3. Protein Structure 20 Amino Acids Coded in DNA Primary Secondary Self assembly to a single (native) structure. Depends on primary structure and solution conditions Tertiary ( ) Quaternary Common in foods. Many non-native forms depending on protein structure, solution conditions (& history) and ingredient interactions Denatured

  4. Amino Acids • The monomer unit of proteins • R is the side chain. • One of 20 different chemical compounds • Some R-groups are acid (other alkali) • Some R-groups are water soluble (others are not) Chiral carbon (L-series)

  5. Polar Uncharged. Ser, Thr, Asn, Gln, Cys Positive (basic). Arg, Lys, His Negative (acidic). Asp, Glu, Non-Polar Aliphatic. Ala, Ile, Leu, Met, Pro, Val Aromatic. Phe, Trp, Tyr Amino Acids

  6. Example Amino Acids Alanine Phenylalanine Glutamic acid

  7. Peptide Bonds Amino acids Water

  8. O C N H Peptide Bonds : - O C N H +

  9. Two cysteine molecules under oxidizing conditions Intermolecular or intramolecular cross-link Disulfide Bonds

  10. N-H to C=O hydrogen bonds in 4th succeeding A.A. Hydrogen bonds parallel to axis Typically amphiphilic a-Helix

  11. Amphiphilic 2° Structures Hydrophilic Hydrophobic

  12. C=O and N-H perpendicular to chain form inter-segment H-bonds Parallel or antiparallel b-strands typically 5-15 A.A. More stable than a-helix b-Sheet b-sheet

  13. Protein Folding Hydrophobic amino acids Peptide chain

  14. Tertiary Structure

  15. Types of Tertiary Structure Globular Disordered Fibrous Many insoluble amino acids, protein tends to minimize surface/volume ratio Interacts well with water and takes up a random configuration Strong secondary structure allows protein to retain a non-spherical shape

  16. Quaternary Structure Folded protein unable to contain some hydrophobic residues Dimerized protein shields the hydrophobic amino acids from water

More Related