title: Evidence for a phosphorylation-induced conformational change in phospholamban from the effects of three proteases.
abstract: The effect of the proteases trypsin, thermolysin and papain on the cardiac membrane protein phospholamban was examined before or after phosphorylating the protein with the catalytic subunit of cyclic AMP-dependent protein kinase. The sensitivity of phospholamban to digestion by trypsin and thermolysin was greatly reduced by phosphorylation, suggesting that phospholamban undergoes a conformational change upon phosphorylation. It is suggested that this change in conformation is the mechanism by which phospholamban phosphorylation relieves its inhibition of the sarcoplasmic reticulum Ca2+-ATPase pump.
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D006168:Guinea Pigs; D009206:Myocardium / Q000032:analysis; D010206:Papain / Q000494:pharmacology*; D010766:Phosphorylation; D011487:Protein Conformation / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000378:metabolism; D013820:Thermolysin / Q000494:pharmacology*; D014357:Trypsin / Q000494:pharmacology*; D000099211:Phospholamban
chemical_list: D002135:Calcium-Binding Proteins; D000252:Calcium-Transporting ATPases; D010206:Papain; D011494:Protein Kinases; D013820:Thermolysin; D014357:Trypsin; D000099211:Phospholamban