CHE 4341 Lecture Notes - Lecture 3: Robert Corey, Disulfide, Transmission Electron Microscopy
Document Summary
Weak collagen (skin lesions, fragile blood vessels, bleeding gums) Collagen fibrils strengthened by: intrachain lysine-lysine interchain hydroxypyridinium covalent crosslinks. Collagen cross-links accumulate over time: increase in cross-links = less elastic collagen meaning more brittle bones/tendons. One form of type ii osteogenesis imperfect occurs when: Prevents the normal production of mature type i collagen. Leads to brittle bones a mutation in a gene for collagen leads to the substitution of gly for another aa. Loops and turns - not common 2 structures . Normally on surface of globular protein (hydrophilic) Gfp = green fluorescent protein the omega loop: the beta turn (beta bend, tight turn) Allows polypeptide in antiparallel -sheet to reverse direction. 4 residues needed to create the quick turn carbonyl o"s are h-bonded to amide h"s b/t residues 1 & 4. Pro often 2nd residue in both types. Results from the folding of polypeptide chain into a closely packed 3d structure b/c of hydrophobic interactions/effects.
