title: Radiation inactivation analysis of sarcoplasmic reticulum Ca-ATPase in membrane-bound form and in detergent-solubilized monomeric states.
abstract: The sarcoplasmic reticulum Ca-ATPase was subjected to target size analysis by radiation inactivation in various buffer conditions and after solubilization in monomeric form in non-ionic detergent and in SDS. The target size was also determined for Ca-ATPase in bidimensional crystals formed in the presence of decavanadate or lanthanide. The standardization obtained with defined monomers of Ca-ATPase shows that the target size of Ca-ATPase in the functional membrane-bound state may be ascribed to a single peptide chain, possibly with surrounding lipid. Further analysis of the radiation inactivation sizes of various partial reactions of the pump cycle, including phosphorylation and Ca2+ occlusion, indicated much smaller values than the target size pertaining to decomposition of the whole peptide chain. This is consistent with the existence of separate functional domains within a single peptide chain.
authors.affiliation: Danish Biotechnology Center for Research in Membrane Transport Proteins, University of Aarhus, Denmark.
authors.forename: J P
authors.initials: JP
authors.lastname: Andersen
authors.forename: B
authors.initials: B
authors.lastname: Vilsen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D001565:Benzoates / Q000494:pharmacology; D019817:Benzoic Acid; D002118:Calcium / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000378:metabolism / Q000528:radiation effects*; D002462:Cell Membrane / Q000201:enzymology; D003460:Crystallization; D003902:Detergents; D005954:Glucosephosphate Dehydrogenase / Q000528:radiation effects; D007811:Lanthanum / Q000494:pharmacology; D046911:Macromolecular Substances; D008970:Molecular Weight; D009132:Muscles / Q000201:enzymology; D010766:Phosphorylation; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D012995:Solubility; D013395:Sucrose / Q000494:pharmacology
chemical_list: D001565:Benzoates; D003902:Detergents; D046911:Macromolecular Substances; C028521:lanthanum chloride; D013395:Sucrose; D007811:Lanthanum; D000255:Adenosine Triphosphate; D019817:Benzoic Acid; D005954:Glucosephosphate Dehydrogenase; D000252:Calcium-Transporting ATPases; D002118:Calcium