title: Large-scale structural changes in the sarcoplasmic reticulum ATPase appear essential for calcium transport.
abstract: Model refinement calculations utilizing the results from time-resolved x-ray diffraction studies indicate that specific, large-scale changes (i.e., structural changes over a large length scale or long range) occur throughout the cylindrically averaged profile structure of the sarcoplasmic reticulum ATPase upon its phosphorylation during calcium active transport. Several physical-chemical factors, all of which slow the kinetics of phosphoenzyme formation, induce specific, large-scale changes throughout the profile structure of the unphosphorylated enzyme that in general are opposite to those observed upon phosphorylation. These results suggest that such large-scale structural changes in the ATPase occurring upon its phosphorylation are required for its calcium transport function.
authors: Department of Chemistry, University of Pennsylvania, Philadelphia 19104.
authors: J K
authors: JK
authors: Blasie
authors: D
authors: D
authors: Pascolini
authors: F
authors: F
authors: Asturias
authors: L G
authors: LG
authors: Herbette
authors: D
authors: D
authors: Pierce
authors: A
authors: A
authors: Scarpa
mesh_terms: D001693:Biological Transport, Active; D002118:Calcium / Q000493:pharmacokinetics*; D000252:Calcium-Transporting ATPases / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D011487:Protein Conformation; D012519:Sarcoplasmic Reticulum / Q000201:enzymology / Q000648:ultrastructure*; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
chemical_list: D000252:Calcium-Transporting ATPases; D002118:Calcium