Defining the minimal structural requirements for partial agonism at the type I myo-inositol 1,4,5-trisphosphate receptor

Add time:08/21/2019    Source:sciencedirect.com

The novel synthetic analogues d-3-fluoro-myo-inositol 1,5-bisphosphate-4-phosphorothioate, [3F-Ins(1,5)P2-4PS], d-3-fluoro-myo-inositol 1,4-bisphosphate-5-phosphorothioate [3F-Ins(1,4)P2-5PS], and d-3-fluoro-myo-inositol 1-phosphate-4,5-bisphosphorothioate [3F-Ins(1)P-(4,5)PS2] were utilised to define the structure-activity relationships which could produce partial agonism at the Ca2+ mobilising myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P3] receptor. Based on prior structure-activity data we hypothesised that the minimal structural requirements for Ins(1,4,5)P3 receptor partial agonism, were phosphorothioate substitution of the crucial vicinal 4,5-bisphosphate pair accompanied by another structural perturbation, such fluorination of 3-position of the myo-inositol ring. All the analogues fully displaced [3H]Ins(1,4,5)P3 from a single Ins(1,4,5)P3 binding site in pig cerebellar membranes [3F-Ins(1,5)P2-4PS (IC50=26 nM), 3F-Ins(1,4)P2-5PS (IC50=80 nM) and 3F-Ins(1)P-(4,5)PS2 (IC50=109 nM) cf. Ins(1,4,5)P3 (IC50=11 nM)]. In contrast, 3F-Ins(1,5)P2-4PS (IC50=424 nM) and 3F-Ins(1,4)P2-5PS (IC50=3579 nM) were weak full agonists at the Ca2+ mobilising Ins(1,4,5)P3 receptor of permeabilised SH-SY5Y neuroblastoma cells, being respectively 4- and 36-fold less potent than Ins(1,4,5)P3 (EC50=99 nM). While 3F-Ins(1)P-(4,5)PS2 (EC50=11345 nM) was a partial agonist releasing only 64.3±1.9% of the Ins(1,4,5)P3-sensitive intracellular Ca2+ pools. 3F-Ins(1)P-(4,5)PS2 was unique among the Ins(1,4,5)P3 receptor partial agonists so far identified in having a relatively high affinity for the Ins(1,4,5)P3 binding site, accompanied by a significant loss of intrinsic activity for Ca2+ mobilisation. This improved affinity was probably due to the retention of the 1-position phosphate, which enhances interaction with the Ins(1,4,5)P3 receptor. 3F-Ins(1)P-(4,5)PS2 may be an important lead compound for the development of efficient Ins(1,4,5)P3 receptor antagonists© 1997 Federation of European Biochemical Societies. All rights reserved.

We also recommend Trading Suppliers and Manufacturers of inositol 1,4-bisphosphate 5-phosphorothioate (cas 116778-73-5). Pls Click Website Link as below: cas 116778-73-5 suppliers

Prev:Synthesis of novel metabolically stable analogues of D-myo-inositol 1,4,5-trisphosphate
Next:The role of inositol 1,4,5-trisphosphate 5-phosphatase in inositol signaling in the CNS of larval Manduca sexta)