BCH210H1 Lecture Notes - Lecture 12: Alpha And Beta Carbon, Tryptophan, Phenylalanine

• School: UTSG
• Department: Biochemistry
• Course: BCH210H1
• Professor: Reinhart Reithmeier

Document Summary

** to fully understand function, we need high resolution of the 3d structure: x-ray crystallography, electron microscopy, nuclear magnetic resolution spectroscopy, infra red spectroscopy, circular dichroism spectroscopy, fluorescence spectroscopy. Only certain proteins form crystal structures: membrane proteins very difficult to form crystal structures, taken out of their natural environment unstable . Surface structures often more mobile less ordered aggregate: less good diffraction pattern. Secreted proteins easily form crystal structures: trypsin, chymotrypsin, hemoglobin, myoglobin. Very high resolution (2 angstroms: can see backbone & side chain, can see every hydrogen atom, can see the (x,y,z) position of every atom. High intensity x-ray beams hit the crystal: yields electron cloud position assume nucleus is in the middle. Yields diffraction pattern phi-psy angles mathematical formulas: yields 3d protein structure. High, but not super high resolution (3. 2 angstroms) Camera captured can make movies (see the changes over time) Best on large particles: usually difficult to crystallize.