Derivatives of thapsigargin as probes of its binding site on endoplasmic reticulum Ca2+ ATPase

FEBS Letters

Poulsen, Jens-Christian J.²  Andersen, Annette¹  Christensen, Søren Brøgger¹  Treiman, Marek² 

[1] PharmaBiotec, Department of Organic Chemistry, The Royal Danish School of Pharmacy, University of Copenhagen, Copenhagen, Denmark;Department of Medical Physiology, Biotechnology Center for Signal Peptide Research, University of Copenhagen, Panun Institute, Blegdamsvej 3C, DK-2200 N Copenhagen, Denmark

关键词: Thapsigargin;    Ca2+ ATPase;    Endoplasmic reticulum;    Ca2+ store;   

DOI  :  10.1016/0014-5793(93)80416-R

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The naturally occurring sesquiterpene lactone thapsigargin is a potent and selective inhibitor of SERCA ATPases, a family of Ca²⁺-pumping ATPases present in the endoplasmic reticulum of all mammalian cells. We have studied some of the molecular features of thapsigargin responsible for its inhibitory action towards these Ca²⁺ ATPases. A series of thapsigargin analogues were synthesised and their inhibitory potencies determined using the uptake of ⁴⁵Ca²⁺ in bovine cerebellar microsomes as a sensitive marker of Ca²⁺ ATPase activity. An attenuation of the inhibitory potency relative to the parent compound was found ranging from slight to over 3 orders of magnitude. The inhibitory activity showed a very strong configuration dependence, a major contribution from the ester groups at C3 and C10, and an apparently minor contribution from the lactone ring substituents. The data are consistent with thapsigargin fitting to a sterically discriminating cleft involving the hydrophobic transmembrane region of the ATPase, and is compatible with available kinetic evidence of thapsigargin-mediated inhibition.

【 授权许可】

Unknown