Purification of the hepatic glycogen-associated form of protein phosphatase-1 by microcystin-Sepharose affinity chromatography.
The form of protein phosphatase-1 associated with hepatic glycogen (PP1G) was purified to near homogeneity from rat liver by affinity chromatography on microcystin-Sepharose and gel-filtration. The enzyme is a heterodimer consisting of the catalytic subunit of PP1 (the alpha and beta isoforms) complexed to a 33 kDa glycogen-binding (GL) subunit. The GL subunit binds phosphorylase a with high affinity, and is responsible for the enhanced dephosphorylation of glycogen synthase by PP1G and its allosteric inhibition by phosphorylase a.
Moorhead
G
G
Department of Biochemistry, University of Dundee, Scotland, UK.
MacKintosh
C
C
Morrice
N
N
Cohen
P
P
D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D002846:Chromatography, Affinity / Q000379:methods*; D002850:Chromatography, Gel; D005895:Gizzard, Avian / Q000201:enzymology; D006003:Glycogen / Q000378:metabolism*; D006006:Glycogen Synthase / Q000378:metabolism; D008099:Liver / Q000201:enzymology*; D046911:Macromolecular Substances; D052998:Microcystins; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010456:Peptides, Cyclic; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification*; D010762:Phosphorylase a / Q000378:metabolism / Q000494:pharmacology; D010766:Phosphorylation; D054645:Protein Phosphatase 1; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar
D046911:Macromolecular Substances; D052998:Microcystins; D010446:Peptide Fragments; D010456:Peptides, Cyclic; C078588:microcystin; D006003:Glycogen; D010762:Phosphorylase a; D006006:Glycogen Synthase; D010749:Phosphoprotein Phosphatases; D054645:Protein Phosphatase 1