ACTA, a fluorescent analogue of thapsigargin, is a potent inhibitor and a conformational probe of skeletal muscle Ca2+-ATPase

TY - JOUR

T1 - ACTA, a fluorescent analogue of thapsigargin, is a potent inhibitor and a conformational probe of skeletal muscle Ca2+-ATPase

AU - Procida, K

AU - Caspersen, C

AU - Kromann, H

AU - Christensen, S B

AU - Treiman, M

N1 - Keywords: Calcium; Calcium-Transporting ATPases; Enzyme Inhibitors; Fluorescent Dyes; Muscle, Skeletal; Protein Conformation; Thapsigargin

PY - 1998

Y1 - 1998

N2 - Thapsigargin is a highly potent and selective inhibitor of sarco-endoplasmic reticulum (SERCA) family of Ca2+-ATPases and a useful tool in research concerning the function of intracellular Ca2+ stores. We describe here a novel fluorescent derivative (8-O-(4-aminocinnamoyl)-8-O-debutanoylthapsigargin, termed ACTA) of this compound, acting as a Ca2+-ATPase inhibitor with a potency approaching that of thapsigargin. Binding of ACTA to the skeletal muscle sarcoplasmic reticulum vesicles results in a strong fluorescence enhancement, approximately 66% of which depends on ACTA association with Ca2+-ATPase. This specific component of ACTA fluorescence is sensitive to the E1-E2 conformational equilibrium of the pump. The combined properties of high potency and binding-dependent fluorescence suggest ACTA to be a useful probe for a range of studies involving the SERCA class of ATPases.

AB - Thapsigargin is a highly potent and selective inhibitor of sarco-endoplasmic reticulum (SERCA) family of Ca2+-ATPases and a useful tool in research concerning the function of intracellular Ca2+ stores. We describe here a novel fluorescent derivative (8-O-(4-aminocinnamoyl)-8-O-debutanoylthapsigargin, termed ACTA) of this compound, acting as a Ca2+-ATPase inhibitor with a potency approaching that of thapsigargin. Binding of ACTA to the skeletal muscle sarcoplasmic reticulum vesicles results in a strong fluorescence enhancement, approximately 66% of which depends on ACTA association with Ca2+-ATPase. This specific component of ACTA fluorescence is sensitive to the E1-E2 conformational equilibrium of the pump. The combined properties of high potency and binding-dependent fluorescence suggest ACTA to be a useful probe for a range of studies involving the SERCA class of ATPases.

M3 - Journal article

C2 - 9849892

SN - 0014-5793

VL - 439

SP - 127

EP - 132

JO - FEBS Letters

JF - FEBS Letters

IS - 1-2

ER -