BCH210H1 Lecture Notes - Lecture 5: Hydrogen Bond, Heme, Schiff Base

• School: UTSG
• Department: Biochemistry
• Course: BCH210H1
• Professor: Stavroula Andreopoulos

Document Summary

How do polypeptides fold into 3d protein structures. Lecture 5: protein structure, special proteins. Several important principles: secondary structures form wherever possible (due to formation of large numbers of h bonds) Formation of large numbers of intramolecular hydrogen bonds. Reduction in the surface area accessible to solvent that occurs upon folding. Stability decreases energy associated with the structure. Folding of a polypeptide (comprised of regions of alpha helices and beta structures) into a closely packed 3d structure. Amino acids great distances apart can be brought into close proximity. Tertiary structure stabilized by covalent and noncovalent interactions. Recognizable combinations of alpha- helices, beta- strands and loops that appear in different proteins are called super secondary structures or motifs. Lactate dehydrogenase and malate dehydrogenase: these 2 have homologous 3d structures, but the primary sequence is very different . 20% similarity: carry out similar functions. Part of the same family of enzymes.