In vitro inhibition of animal and higher plants 2,3-oxidosqualene-sterol cyclases by 2-aza-2,3- dihydrosqualene and derivatives, and by other ammonium-containing molecules

Duriatti, Albert; Bouvier-Navé, Pierrette; Benveniste, Pierre; Schuber, Francis; Delprino, Laura; Balliano, Gianni; Cattel, Luigi

doi:10.1016/0006-2952(85)90578-7

Cited by 92 publications

(56 citation statements)

References 65 publications

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“…However, the inhibitors are used in concentrations far below their critical micelle concentration and would be able to diffuse as molecules with molecular masses of about 0.4 kDa. Therefore the extremely high inhibition potential of the inhibitors tested by us, as well as by Duriatti et al [33] might only be the result of very different diffusion rates of the substrate and inhibitor.…”

Section: Properties Of Squalene-hopene Cyclasementioning

confidence: 75%

Properties of purified squalene‐hopene cyclase from Bacillus acidocaldarius

Ochs

Tappe

Gärtner

et al. 1990

European Journal of Biochemistry

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The squalene-hopene cyclase from Bacillus acidocaldarius cytoplasmic membrane, was purified to homogeneity by solubilization with Triton X-100, chromatography on DEAE-cellulose, phenyl Sepharose and two gel-filtration columns. The enzyme monomer had a molecular mass of 75 kDa. The sequence of the first 23 amino acids was determined by Edman degradation. The enzyme activity was efficiently inhibited by n-alkyldimethylammonium halides with alkyl chain lengths between 12 and 18 C atoms. Inhibition was also observed with (5-hydroxycarvacry1)trimethylammonium chloride I-piperidine carboxylate, dodecyldimethylamine N-oxide, azasqualene and farnesol. Competitive inhibition with dodecyltrimethylammonium bromide, (5-hydroxycarvacry1)trimethylammonium chloride I-piperidine carboxylate and dodecyldimethylamine N-oxide was demonstrated by Lineweaver-Burk plots.Tetracyclic and pentacyclic triterpenoids are widespread metabolites. Derivatives of hopan, lupan, fernan, olean, ursan, gammaceran and different sterols occur in plants [l]. Sterols (e.g. cholesterol, sitosterol, stigmasterol and ergosterol) are found in animals and plants as membrane lipids [l]. In contrast, the occurrence and especially the synthesis of sterols is very rare in bacteria [2]. However, hopanoids, exclusively those with an elongated side chain, are frequently found in bacterial membranes [2], and have a similar function to sterols, condensing phospholipids above the transition temperature in model membrane systems [3, 41 and presumably also in biological membranes [5].Hopanoids are cyclized from squalene [6], whereas sterols are synthesized from squalene epoxide [7, 81. The molecular oxygen dependence for the synthesis of squalene epoxide and for the demethylation reactions in membrane sterol synthesis, support the hypothesis that sterol biosynthesis is a modern metabolic evolutionary trait in comparison to hopanoid biosynthesis [S -101.We are interested in the question of homology between the squalene and squalene-epoxide cyclases and also in the exact amino acid alterations necessary for the postulated evolution of squalene cyclase to a modern squalene-epoxide cyclase. This issue is now possible since another group has purified squalene-epoxide cyclases for amyrins and cycloartenol from plants [I1 -131 and therefore a basis is laid for a future sequence comparison of the different cyclase genes.In this paper we describe the purification, N-terminal amino acid sequence, and the effect of new inhibitors of [4, 8, 12, 17, 21-3H]Squalene was purchased from New England Nuclear (Dreieich, FRG); unlabeled squalene, (5-hydroxycarvacry1)trimethylammonium chloride 1-piperidine carboxylate (AM0 161 8) dodecyldimethylamine N-oxide (DodMe2NO), dodecyltrimethylammonium bromide (DodMe3NBr), taurodeoxycholate, Chaps, N-lauroylsarcosine and trypsin inhibitor from Sigma; DEAE-cellulose, Sevacel SH-23 and Triton X-100 from Serva; phenyl-Sepharose CL4B, Sephacryl S-300 and Sephacryl S-500 from Pharmacia; sodium taurocholate from Aldrich. MATERIALS AND METHODS Chemical...

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Section: Properties Of Squalene-hopene Cyclasementioning

confidence: 75%

Properties of purified squalene‐hopene cyclase from Bacillus acidocaldarius

Ochs

Tappe

Gärtner

et al. 1990

European Journal of Biochemistry

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“…A class 2 amphiphilic hydrophobic amine, U18666A interferes with intracellular cholesterol transport through inhibition of desmosterol reductase, the enzyme responsible for reducing desmosterol to cholesterol in the cholesterol biosynthetic pathway (6,62). It also inhibits an additional component involved in cholesterol synthesis, oxidosqualene cyclase (13,70). This well-studied compound has been shown to induce an NPC disease-like phenotype, with respect to cholesterol accumulation in normal cells (55,60,66).…”

Section: U18666a Treatment Of Cells Causes Cholesterol Accumulationmentioning

confidence: 99%

Deficiency of Niemann-Pick Type C-1 Protein Impairs Release of Human Immunodeficiency Virus Type 1 and Results in Gag Accumulation in Late Endosomal/Lysosomal Compartments

Tang

Leao

Coleman

et al. 2009

J Virol

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“…The azasqualene derivatives, which were designed as analogs of the high-energy carbocationic intermediates generated at C-2 after the opening of the oxiranic ring, or at C-19, after the closure of the fourth ring, have been well studied as inhibitors of mammalian and fungal OSC (15,25,26). From the comparison of the IC 50 obtained with the T. cruzi and with the pig and S. cerevisiae OSC, these compounds do not show specificity for the T. cruzi enzyme, probably because the mechanism of the initial step of the cyclization is very conserved in all the OSC (13).…”

Section: Discussionmentioning

confidence: 99%

“…The synthesis of the inhibitors tested (compounds 1-19 of Fig. 2) has been described elsewhere (16,17,19,20,23,25,26). The identity and purity of inhibitors was checked by TLC, 1 H NMR and mass spectra before testing the inhibition of T. cruzi OSC.…”

Section: Materials Substrates and Test Compoundsmentioning

confidence: 99%

Analogs of squalene and oxidosqualene inhibit oxidosqualene cyclase of Trypanosoma cruzi expressed in Saccharomyces cerevisiae

Oliaro‐Bosso

Ceruti

Balliano

et al. 2005

Lipids

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ABSTRACT:Recently, a number of inhibitors of the enzyme oxidosqualene cyclase (OSC; EC 5.4.99.7), a key enzyme in sterol biosynthesis, were shown to inhibit in mammalian cells the multiplication of Trypanosoma cruzi, the parasite agent of Chagas' disease. The gene coding for the OSC of T. cruzi has been cloned and expressed in Saccharomyces cerevisiae. The expression in yeast cells could be a safe and easy model for studying the activity and the selectivity of the potential inhibitors of T. cruzi OSC. Sterols are eukaryotic membrane components that are necessary to support cell growth and differentiation. Sterol biosynthesis is a well-established chemotherapeutic target in pathogenic eukaryotes, such as fungi (1,2). The final product of the sterol biosynthetic pathway in fungi is the 24-alkyl sterol ergosterol. Ergosterol or similar 24-alkyl sterols are also the final products of the sterol synthetic pathway of some pathogenic protozoa including Trypanosoma species. These organisms cannot completely substitute these sterols with the cholesterol biosynthesized in host mammalian cells and need to synthesize at least some of their own distinctive sterols (3-5). This dependence on sterols suggests that sterol biosynthesis inhibitors may be useful antiprotozoal drugs. The sterol biosynthetic pathway ( Fig. 1) offers many potential targets for therapeutic purposes. Many effective antifungal drugs already in use act by inhibiting different enzymes of sterol biosynthesis; the allylamine antifungal drug terbinafine inhibits squalene epoxidase (6), and azole drugs such as ketoconazole and itraconazole are inhibitors of lanosterol C 14 -demethylase (7). The activity of these inhibitors can be explained as a consequence either of depletion of the ergosterol or of accumulation of toxic intermediates or side products. In addition to the antifungal activity, some of these compounds Acetyl-CoAwere shown to inhibit the growth of Trypanosoma and other kinetoplastid parasites (8). Kinetoplastid parasites have also been shown recently to be susceptible to inhibitors of squalene synthase (9,10) and oxidosqualene cyclase (11,12). The enzyme oxidosqualene cyclase (OSC; EC 5.4.99.7), which catalyzes the formation of the first cyclic precursor of sterols, is considered a good target for the inhibition of sterol biosynthesis in both humans and fungi. Many inhibitors, designed on the basis of the complex cyclization mechanism of OSC (13), are active on the enzyme and have been investigated as potential cholesterol-lowering or antifungal drugs (1,2,13). The recent crystallization of human OSC as a complex with the potent inhibitor RO48-8071 opens the way to new structurebased studies of the cyclization mechanism (14).We have designed and tested against mammalian and fungal OSC many acyclic substrate analogs modified either to mimic the high-energy carbocationic intermediates (compounds 1-3 of Fig. 2) or to bear reactive functions able to interact with the active site residues, as the methylidene (compounds 4-8), vinyl sulfide (compounds 9...

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In vitro inhibition of animal and higher plants 2,3-oxidosqualene-sterol cyclases by 2-aza-2,3- dihydrosqualene and derivatives, and by other ammonium-containing molecules

Cited by 92 publications

References 65 publications

Properties of purified squalene‐hopene cyclase from Bacillus acidocaldarius

Properties of purified squalene‐hopene cyclase from Bacillus acidocaldarius

Deficiency of Niemann-Pick Type C-1 Protein Impairs Release of Human Immunodeficiency Virus Type 1 and Results in Gag Accumulation in Late Endosomal/Lysosomal Compartments

Analogs of squalene and oxidosqualene inhibit oxidosqualene cyclase of Trypanosoma cruzi expressed in Saccharomyces cerevisiae

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