BIOC 3560 Lecture Notes - Lecture 10: Glycogen Phosphorylase, Dicoumarol, Amine

• School: University of Guelph
• Department: Biochemistry
• Course: BIOC 3560
• Professor: Manfred Brauer

Document Summary

Phosphoryl groups introduce: a relatively large group, charge: allowing electrostatic interactions, oxygen atoms can participate in h-bonds, site for protein-protein interaction. Example 1: glycogen phosphorylase (gp) (kinase: is activated by phosphorylation of a serine oh. Fast energy, glucose units from muscle glycogen rapidly mobilized for glycolytic energy. Phosphorylation of ser 14 favours the r state. Reciprocal regulation: phosphorylation activates gp (for energy) and inactivates. Example 2: phosphorylation of tyrosine-oh src-homology-2 (sh2) domains can bind to sites containing phosphorylated tyrosines: protein-protein interaction, mediated by sh2 domains, are an important part of insulin signalling, phosphotyrosine binding sites (sh2) on proteins involved in cell proliferation. Sh2 domain function: if you phosphorylated tyrosine of src kinase, it is auto inhibited (bind to itself, not downstream target protein). Remember pseudo-subsrate in pka: when you want to activate it, you need to dephosphorylate the tyrosine so that the sh2 can be freed up and it can associate with the downstream proteins.