1. SCID 141 - Living Process: From Molecules to Cell
Instructor: Kittisak Yokthongwattana, Ph.D.
Department of Biochemistry, Faculty of Science, Mahidol University
Amino Acids and Proteins

2. Amino Acids

3. Stereo Chemistry of Amino Acids

4. Different Side Chains of Amino Acids

5. Different Side Chains of Amino Acids

6. Different Side Chains of Amino Acids

7. Different Side Chains of Amino Acids

8. Different Side Chains of Amino Acids

9. Amino Acid Abbreviation

10. Amino Acid Abbreviation

11. Covalent Bond Formation Between Amino Acids – disulfide bond

12. Protonation States of Amino Acids

13. Protonation States of Amino Acids

14. Peptide Bond Formation

15. Polypeptide Chain – primary structure

16. Polypeptide Chain Folds Into Secondary Structure

17.  AND  ANGLES

18. Ramachandran plot
Image from Voet and Voet, Biochemistry, 4th Edition, 2011

19. What do  AND  ANGLES signify?
Image from Voet and Voet, Biochemistry, 4th Edition, 2011

20. Polypeptide Chain Folds Into Secondary Structure – alpha helix

21. Molecular Interaction stabilizing secondary structure is hydrogen bond
Image from Lippincott, Fig. 2.6

22. Polypeptide Chain Folds Into Secondary Structure – alpha helix

23. Polypeptide Chain Folds Into Secondary Structure – Beta Sheet

24. Polypeptide Chain Folds Into Secondary Structure – Beta Sheet

25. Secondary Structures fold into tertiary structure

26. Intermolecular Interactions that stabilize tertiary structure
Disulfide bond formation
Hydrophobic interaction
Images from Lippincott, Fig. 2.9, 2.10

27. Intermolecular Interactions that stabilize tertiary structure
Ionic interaction
Images from Lippincott, Fig. 2.11

28. Soluble Protein

29. Chaperone-Assisted Protein Folding – DnaK/DnaJ SYSTEM

30. Chaperone-Assisted Protein Folding – GroEL/GroES SYSTEM

31. Transmembrane protein

32. Transmembrane protein

33. Transmembrane protein

34. Transmembrane protein
Aquaporin

35. Voltage-Gated K+ Channel

36. Example of Chloride Channel

37. Quaternary Structure of protein is the assembly of tertiary structures

38. Disulfide bond formation also stabilizes protein quaternary structure

39. Protein folding signifies functions

40. Collagen is a triple-helix protein
The stability of collagen triple helices rely on a sharp turn of the helix caused by an amino acid called hydroxyproline. Hydroxyproline is produced by hydroxylation of the amino acid proline by the enzyme prolyl hydroxylase following its de novo synthesis (as a post-translational modification). Such reaction, which requires vitamin C, takes place in the lumen of the endoplasmic reticulum.

41. Actin – Myosin are major proteins in myocytes

42. Actin – Myosin are major proteins in myocytes

43. Actin – Myosin are major proteins in myocytes

44. Myosin motor

45. Actin

46. Movement of myosin motor on Actin filament

47. Immunoglobulin proteins - IgG

48. Immunoglobulin proteins

49. Immunoglobulin proteins - IgM

50. Phagocytosis of an antibody-bound virus by a macrophage

51. Hemoglobin
Hemoglobin
Myoglobin

52. Heme structure within hemoglobin upon Oxygen binding

53. The Bohr Effect
CO2 and H+ ions also are effectors of hemoglobin. In active muscle cells, oxygen is rapidly consumed and carbon dioxide and H+ ions are produced.
O2 affinity decreases at lower pH. As hemoglobin moves into a tissue with lower pH, it can more easily unload oxygen.
Increase in CO2 concentrations have the same effect.
In combination, the effect of pH and CO2 allow nearly 90% of the oxygen bound in the lungs to be unloaded in tissues where it is required.

54. Structural Basis of the Bohr Effect

55. BPG Binding Stabilizes the T state

56. Sickle Cell Anemia