title: Calcium transport by sarcoplasmic reticulum Ca-ATPase can be investigated on a solid-supported membrane.
abstract: Sarcoplasmic reticulum (SR) native vesicles incorporating Ca-ATPase are adsorbed on a solid-supported lipid membrane (SSM). Upon adsorption, the ion pumps are chemically activated by concentration jumps of ATP and the capacitive current transients generated by SR Ca-ATPase are measured under potentiostatic conditions. The Michaelis-Menten constant, K(M), for ATP is evaluated by varying the concentration of ATP in the activating solution. This preliminary result shows that ion transport by SR Ca-ATPase can be suitably investigated by a technique based on concentration jumps on an SSM.
authors.affiliation: Laboratory of Bioelectrochemistry, Chemistry Department, University of Florence, via della Lastruccia 3, 50019 Sesto Fiorentino, Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Bartolommei
authors.forename: F Tadini
authors.initials: FT
authors.lastname: Buoninsegni
authors.forename: M R
authors.initials: MR
authors.lastname: Moncelli
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000327:Adsorption; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000502:physiology*; D018929:Cell Culture Techniques / Q000379:methods*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D025802:Electric Capacitance; D004563:Electrochemistry / Q000379:methods*; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D008567:Membranes, Artificial; D010743:Phospholipids / Q000737:chemistry; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000502:physiology*
chemical_list: D008567:Membranes, Artificial; D010743:Phospholipids; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases; D002118:Calcium