https://ogma.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20160 36-fold reduced activity against rings, suggesting that they can discriminate between helical or ring oligomerization states. 4a and 6a inhibited dynamin-dependent endocytosis of transferrin in multiple cell types (IC50 of 5.7 and 5.8 μM, respectively), at least sixfold more potently than dynasore, but had no effect on dynamin-independent endocytosis of cholera toxin. 4a also reduced synaptic vesicle endocytosis and activity-dependent bulk endocytosis in cultured neurons and synaptosomes. Overall, 4a and 6a are improved and versatile helical dynamin and endocytosis inhibitors in terms of potency, non-specific binding and cytotoxicity. The data further suggest that the ring oligomerization state of dynamin is not required for clathrin-mediated endocytosis.]]> Tue 24 Aug 2021 14:23:34 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:21428 50 ≈ 18 μM). A second library targeting the 4-aminobenzyl moiety was developed, and four analogues displayed comparable activity (26, 27, 28, 34 with IC₅₀ values of 22, 16, 15, and 15 μM respectively) with a further four (24, 25, 32, 33) more active than 18 with IC₅₀ values of 10, 6.9, 12, and 10 μM, respectively. Docking studies rationalized the structure–activity relationship (SAR) with the biological data. 3-Sulfo-N-benzyl-1,8-naphthalimide, potassium salt (25) with an IC50 ≈ 6.9 μM, is the most potent clathrin terminal domain–amphiphysin inhibitor reported to date.]]> Sat 24 Mar 2018 08:05:47 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20625 Sat 24 Mar 2018 07:55:46 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:28474 in silico docking studies. Docking studies predicted enhanced Pitstop® 2 family binding, not a loss of binding, within the Pistop® groove of the reported clathrin mutant invalidating recent assumptions of poor selectivity for this family of clathrin inhibitors.]]> Sat 24 Mar 2018 07:39:34 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:27301 50 2.6±0.7µm). They also inhibited dynamin II (dynII) at similar concentrations. Typical and atypical APDs not based on the phenothiazine scaffold were 8- to 10-fold less potent (haloperidol and clozapine) or were inactive (droperidol, olanzapine and risperidone). Kinetic analysis showed that phenothiazine-derived APDs were lipid competitive, while haloperidol was uncompetitive with lipid. Accordingly, phenothiazine-derived APDs inhibited dynI GTPase activity stimulated by lipids but not by various SH3 domains. All dynamin-active APDs also inhibited transferrin (Tfn) CME in cells at related potencies. Structure-activity relationships (SAR) revealed dynamin inhibition to be conferred by a substituent group containing a terminal tertiary amino group at the N2 position. Chlorpromazine was previously proposed to target AP-2 recruitment in the formation of clathrin-coated vesicles (CCV). However, neither chlorpromazine nor thioridazine affected AP-2 interaction with amphiphysin or clathrin. Super-resolution microscopy revealed that chlorpromazine blocks neither clathrin recruitment by AP-2, nor AP-2 recruitment, showing that CME inhibition occurs downstream of CCV formation. Overall, potent dynamin inhibition is a shared characteristic of phenothiazine-derived APDs, but not other typical or atypical APDs, and the data indicate that dynamin is their likely in-cell target in endocytosis.]]> Sat 24 Mar 2018 07:38:33 AEDT ]]>