Dynamin is required for clathrin-mediated endocytosis (CME). Its GTPase activity is stimulated by phospholipid binding to its PH domain, which induces helical oligomerization. We've made a series of novel pyrimidine-based "Pyrimidyn" Stattic compounds that inhibit the lipid-stimulated GTPase activity of full length dynamin I and II with very similar potency. By far the most potent analogue, Pyrimidyn 7, has an IC50 of one.one mu M for dynamin I and 1.eight mu M for dynamin II, making it between quite possibly the most potent dynamin inhibitors identified to date. We investigated the mechanism of action from the Pyrimidyn compounds in detail by examining the kinetics of Pyrimidyn 7 inhibition of dynamin. The compound competitively inhibits both GTP and phospholipid interactions with dynamin I.
Although each mechanisms of action are previously observed separately, this is certainly the primary inhibitor series to include the two and thereby to target two distinct Topotecan HCl domains of dynamin. Pyrimidyn 6 and seven reversibly inhibit CME of the two transferrin and EGF in the number of non-neuronal cell lines as well as inhibiting synaptic vesicle endocytosis (SVE) in nerve terminals. For that reason, Pyrimidyn compounds block endocytosis by right competing with GTP and lipid binding to dynamin, limiting both the recruitment of dynamin to membranes and its activation. This dual mode of action supplies a significant new device for molecular dissection of dynamin's selleck chem position in endocytosis.