Molecular Biology Of The Cell 6th Edition by Bruce Alberts, Alexander Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter

Exercise 1

A small portion of a two-dimensional display of proteins from human brain is shown in Figure Q7-1. These proteins were separated on the basis of size in one dimension and electrical charge (isoelectric point) in the other. Not all protein spots on such displays are products of different genes; some represent modified forms of a pro- tein that migrate to different positions. Pick out a couple of sets of spots that could represent proteins that differ by the number of phosphates they carry. Explain the basis for your selection.