Selective Transformations of the Ca2+ Pump Inhibitor Thapsigargin.

Andersen, Andreas; Cornett, Claus; Lauridsen, Annette; Olsen, Carl Erik; Christensen, S. Brøgger; Kondow, A. J.; Bisht, Kirpal S.; Parmar, Virinder S.; Francis, George W.

doi:10.3891/acta.chem.scand.48-0340

Cited by 21 publications

(22 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In terms of structure-activity relationships (SAR), very small changes in structure have very profound effects on the analogs' potency in inhibiting purified SERCA ATPase activity, suggesting that that the thapsigargin binding site is very restrictive (Christensen et al, 1992(Christensen et al, , 1997Andersen et al, 1994;Nielsen et al, 1995). In particular, epimerization of C(8) decreases potency by more than 3000 times, and epimerization at C(3) reduces it by 40 times.…”

Section: Pharmacological Modulation Of Smooth Muscle Sr 453mentioning

confidence: 99%

Pharmacological Modulation of Sarcoplasmic Reticulum Function in Smooth Muscle

2004

View full text Add to dashboard Cite

Section: Pharmacological Modulation Of Smooth Muscle Sr 453mentioning

confidence: 99%

Pharmacological Modulation of Sarcoplasmic Reticulum Function in Smooth Muscle

2004

View full text Add to dashboard Cite

“…250 nM) were not significantly different from those recorded in controls. To test further if some other nonspecific effects of thapsigargin could account for our results, we treated cells with an analog of the compound epimerized at C-8 (neo-thapsigargin) (16). When used at low concentrations, this analog of thapsigargin is virtually inactive as an inhibitor of SERCA (17).…”

Section: Amplification Of Calcium Signalingmentioning

confidence: 99%

Ca2+-induced Ca2+ Release from the Endoplasmic Reticulum Amplifies the Ca2+ Signal Mediated by Activation of Voltage-gated L-type Ca2+ Channels in Pancreatic β-Cells

Lemmens

Larsson

Berggren

et al. 2001

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…These desubstituted derivatives were prepared by previously described methods (17,28,29), but we note that the unavailability of desoctanoyl Tg forced us to use as a model compound the previously described dihydronortrilobolide, which differs from desoctanoyl Tg by having a saturated bond between C-4 and C-5 (30). From the activity/inhibitor concentration curves, we find for all desubstituted compounds substantial reductions in the affinity, from a subnanomolar value (0.2 nM) for unmodified Tg to 3.5-113 nM after loss of the side chains.…”

Section: Thapsigargin-ca 2ϩ -Atpase Structure and Interaction-inmentioning

confidence: 99%

Critical Roles of Hydrophobicity and Orientation of Side Chains for Inactivation of Sarcoplasmic Reticulum Ca2+-ATPase with Thapsigargin and Thapsigargin Analogs

Winther

Liu

Sonntag

et al. 2010

Journal of Biological Chemistry

100

View full text Add to dashboard Cite

Thapsigargin (Tg), a specific inhibitor of sarco/endoplasmic Ca 2؉ -ATPases (SERCA), binds with high affinity to the E2 conformation of these ATPases. SERCA inhibition leads to elevated calcium levels in the cytoplasm, which in turn induces apoptosis. We present x-ray crystallographic and intrinsic fluorescence data to show how Tg and chemical analogs of the compound with modified or removed side chains bind to isolated SERCA 1a membranes. This occurs by uptake via the membrane lipid followed by insertion into a resident intramembranous binding site with few adaptative changes. Our binding data indicate that a balanced hydrophobicity and accurate positioning of the side chains, provided by the central guaianolide ring structure, defines a pharmacophore of Tg that governs both high affinity and access to the protein-binding site. Tg analogs substituted with long linkers at O-8 extend from the binding site between transmembrane segments to the putative N-terminal Ca 2؉ entry pathway. The long chain analogs provide a rational basis for the localization of the linker, the presence of which is necessary for enabling prostate-specific antigen to cleave peptide-conjugated prodrugs targeting SERCA of cancer cells (Denmeade, S. R., Jakobsen, C. M., Janssen, S., Khan, S. R., Garrett, E. S., Lilja, H., Christensen, S. B., and Isaacs, J. T. (2003) J. Natl. Cancer Inst. 95, 990 -1000). Our study demonstrates the usefulness of a simple in vitro system to test and direct development toward the formulation of new Tg derivatives with improved properties for SERCA targeting. Finally, we propose that the Tg binding pocket may be a regulatory site that, for example, is sensitive to cholesterol.Understanding protein-membrane interaction and the activity of lipophilic drugs and specific lipids like sterols attracts increasing attention and represents a challenge to our current models of protein-solvent interactions and protein dynamics. Sarco/endoplasmic Ca 2ϩ -ATPase (SERCA) 6 offers an attractive model for the analysis of such interactions due to favorable biochemical properties with sensitive assays of function, a large resource of inhibitors, and a wealth of crystal structures related to the functional cycle. In conjunction with plasma membrane Ca 2ϩ -ATPases and Ca 2ϩ channel proteins, SERCA orchestrates spatiotemporal changes in the concentration of Ca 2ϩ inside the cell, providing the background essential for the function of Ca 2ϩ as a second messenger in the regulation of numerous cellular processes (1-3). At the same time, high cytosolic (Ͼ1 M) concentrations of Ca 2ϩ , induced by depletion of the endoplasmic Ca 2ϩ stores and uptake of extracellular Ca 2ϩ by the endoplasmic store-regulated mechanism (4), are involved as essential factors in the induction of apoptotic processes, leading to mitochondrial disruption with release of cytochrome c, activation of intracellular caspases, and cell death (5). As a consequence, interference of cellular function by inhibition of SERCA may lead to apoptotic cell death irrespective of the...

show abstract

Selective Transformations of the Ca2+ Pump Inhibitor Thapsigargin.

Cited by 21 publications

References 0 publications

Pharmacological Modulation of Sarcoplasmic Reticulum Function in Smooth Muscle

Pharmacological Modulation of Sarcoplasmic Reticulum Function in Smooth Muscle

Ca2+-induced Ca2+ Release from the Endoplasmic Reticulum Amplifies the Ca2+ Signal Mediated by Activation of Voltage-gated L-type Ca2+ Channels in Pancreatic β-Cells

Critical Roles of Hydrophobicity and Orientation of Side Chains for Inactivation of Sarcoplasmic Reticulum Ca2+-ATPase with Thapsigargin and Thapsigargin Analogs

Contact Info

Product

Resources

About