title: Acylspermidine derivatives isolated from a soft coral, Sinularia sp, inhibit plant vacuolar H(+)-pyrophosphatase.
abstract: H(+)-pyrophosphatase (H(+)-PPase), which pumps H(+) across membranes coupled with PP(i) hydrolysis, is found in most plants, and some parasitic protists, eubacteria and archaebacteria. We assayed a number of extracts derived from 145 marine invertebrates as to their inhibitory effect on plant vacuolar H(+)-PPase. Acylspermidine derivatives [RCONH(CH(2))(3)N(CH(3))(CH(2))(4)N(CH(3))(2)] from a soft coral (Sinularia sp.) inhibited the PPi-hydrolysis activity of purified H(+)-PPase and the PP(i)-dependent H(+) pump activity (half inhibition concentration, 1 micro M) of vacuolar membranes of mung bean. The apparent K(i) was determined to be 0.9 micro M. Acylspermidines did not affect the activity of vacuolar H(+)-ATPase, plasma membrane H(+)-ATPase, mitochondrial ATPase or cytosolic PPase. Acylspermidines inhibited the acidification of vacuoles in protoplasts, as found on monitoring by the acridine orange fluorescent method. These results indicate that acylspermidine derivatives represent new inhibitors of H(+)-PPase with relatively high specificity.
authors.affiliation: Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601.
authors.forename: Megumi
authors.initials: M
authors.lastname: Hirono
authors.forename: Makoto
authors.initials: M
authors.lastname: Ojika
authors.forename: Hisatoshi
authors.initials: H
authors.lastname: Mimura
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Nakanishi
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Maeshima
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000378:metabolism / Q000494:pharmacology*; D007887:Fabaceae / Q000201:enzymology; D043564:Inorganic Pyrophosphatase / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000378:metabolism; D013095:Spermidine / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology; D013379:Substrate Specificity; D014617:Vacuoles / Q000201:enzymology
chemical_list: D004791:Enzyme Inhibitors; D043564:Inorganic Pyrophosphatase; D013095:Spermidine