BIOL 301 Lecture Notes - Lecture 7: Stoichiometry, Ubiquitin, Microtubule
Document Summary
Proteins interact with tons other proteins simultaneously: length scale that we"re working with, single cell = 1 um, visible wavelength = ~400nm, proteins: antibodies, biomolecules, complexes: few nm, ribosome nanomachine subunits s9, rack1, l4. Indirect (l4-rack1: 8nm distance from s9 to rack1 incl diameters. Ribosome is 30nm diameter: can"t use regular fluorescence microscopy, resolution too low to resolve/visualise ppi you"d see the two tagged proteins on top of each other (co-localized) but irl they could be not even touching or interacting . Proteins can be in the same place and not interact! So need to use other techniques that don"t involve microscopy . Bifc: bimolecular fluorescence complementation: make bait and prey molecules, bait: n-half of fp fused with protein a, prey: c-half of fp fused with proteins b, c, d, etc, co-express bait and prey in the organism. If bait + prey bind, then fp will become function and fluorescence will be seen.
