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Sterol Biosynthesis Inhibitors: Potential for Transition State Analogs and Mechanism-Based Inactivators Targeted at Sterol Methyltransferase

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Lipids

Abstract

Sterol biosynthesis inhibitors (SBIs), discovered in the late 1960s and subsequently used commercially to treat ergosterol-dependent fungal diseases, represent a unique drug class targeted at an enzyme in a biosynthetic pathway. To date, few drugs have been commercialized as enzyme inhibitors; yet, prescription of SBIs has emerged as the gold standard for some cases of non-life-threatening antifungal chemotherapy and in crop protection. SBIs are not designed for their structural resemblance to the sterol molecule; they nonetheless can engender a curative effect by interfering with sterol production and homeostasis in the pathogenic organism. The increased use of SBIs in recent years, particularly the azole antifungals, has resulted in the development of resistance to those drugs, necessitating additional work to further our understanding of antifungal resistance and to explore opportunities to develop new enzyme inhibitors and uncover new enzyme targets that can regulate carbon flux in the post-lanosterol/cycloartenol pathway. This article reports general considerations for enzyme mechanism and active-site probes using inhibitors of the C-methylation reaction, including a potential new class of antifungal/antiparasitic agents of phytosterol synthesis tailored as mechanism-based inactivators. These steroid-based compounds prepared with different sterol side chain functionalities are designed to reversibly or irreversibly impair the sterol methyltransferase, an enzyme expressed in pathogenic microbes and plants but not in the human host. The salient aspects of these and related topics directed toward the enzyme recognition of sterol structure, and the inhibitory properties and catalytic competence of a series of specifically modified substrate analogs that affect sterol methyltransferase action are discussed.

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References

  1. Roberts CW, McLeod R, Rice DW, Ginger M, Chance ML, Goad JJ (2003) Fatty acid and sterol metabolism: potential antimicrobial targets in apicomplexan and trypansomatid parasitic protozoa. Mol Biochem Parasitol 126:129–142

    Google Scholar 

  2. Burbiel J, Bracher F (2003) Azasteroids as antifungals. Steroids 68:587–594

    Article  PubMed  CAS  Google Scholar 

  3. Rahier A, Taton M (1997) Fungicides as tools in studying postsqualene sterol synthesis in plants. Pest Biochem Physiol 57:1–27

    Article  CAS  Google Scholar 

  4. Berg D, Plempel M (1988) Sterol biosynthesis inhibitors: pharmaceutical and agrochemical aspects. Ellis Horwood, Chichester, UK, p 583

  5. Rahier A, Taton M, Bouvier-Nave P, Schmitt P, Benveniste P, Schuber F, Narula AS, Cattel L, Anding C, Place P (1986) Design of high energy intermediate analogues to study sterol biosynthesis in higher plants. Lipids 21:52–62

    Article  CAS  Google Scholar 

  6. Jayasimha J, Bowman CB, Pedroza JM, Nes WD (2006) Engineering pathway enzymes to understand the function and evolution of sterol structure and activity. Rec Adv Phytochem 40:211–251

    Article  CAS  Google Scholar 

  7. Nes WR, Sekula BC, Nes WD, Adler JH (1978) The functional significance of structural features of ergosterol. J Biol Chem 253:6218–6225

    PubMed  CAS  Google Scholar 

  8. Pinto WJ, Nes WR (1983) Stereochemical specificity for sterols in Saccharomyces cerevisiae. J Biol Chem 258:4472–4476

    PubMed  CAS  Google Scholar 

  9. Nes WD (1987) Biosynthesis and requirement for sterols in the growth and reproduction of oomycetes. Am Chem Soc Symp Ser 325:304–328

    CAS  Google Scholar 

  10. Rodriquez RJ, Low C, Bottema CDK, Parks LW (1985) Multiple functions for sterols in Saccharomyces cerevisiae. Biochim Biophys Acta 837:336–343

    Google Scholar 

  11. Bloch KE (1983) Sterol structure and membrane function. CRC Crit Rev Biochem 14:47–82

    PubMed  CAS  Google Scholar 

  12. Nes WR, Nes WD (1980) Lipids in evolution. Plenum, New York, p 244

  13. Nes WD, Norton RA, Crumley FG, Madigan SJ, Katz ER (1990) Sterol phylogenesis and algal evolution. Proc Natl Acad Sci USA 87:7565–7569

    Article  PubMed  CAS  Google Scholar 

  14. Zhou W, Cross GAM, Nes WD (2006) Cholesterol import fails to prevent catalyst-based inhibition of ergosterol synthesis and cell proliferation of Trypanosoma brucei. J Lipid Res (in press)

  15. Zhou W, Nguyen TTM, Collins MS, Cushion MT, Nes WD (2002) Evidence for multiple sterol methyltransferase pathways in Pneumocystis carinii. Lipids 37:1177–1186

    Article  PubMed  CAS  Google Scholar 

  16. Nes WD, Xu X, Haddon WF (1988) Evidence for similarities and differences in the biosynthesis of fungal sterols. Steroids 53:533–558

    Article  Google Scholar 

  17. Nes WD, Nichols SD (2006) Phytosterol biosynthesis pathway in Mortierella alpine. Phytochemistry 67:1716–1721

    Article  CAS  Google Scholar 

  18. Zhou W, Nes WD (2000) Stereochemistry of hydrogen introduction at C-25 in ergosterol synthesized by the mevalonate-independent pathway. Tetrahedron Lett 41:2791–2795

    Article  CAS  Google Scholar 

  19. Lichtenthaler HK (1999) The 1-deoxy-D-xylulose-5-phosphate pathway of isoprenoid biosynthesis in plants. Annu Rev Plant Physiol Mol Biol 50:47–65

    Google Scholar 

  20. Zhou W, Lepesheva GI, Waterman MR, Nes WD (2006) Mechanistic analysis of multiple product sterol methyltransferase implicated in ergosterol biosynthesis in Trypanosoma brucei. J Biol Chem 281:6290–6296

    Article  PubMed  CAS  Google Scholar 

  21. Nes WD (2005) Enzyme redesign and interactions of substrate analogues with sterol methyltransferase to understand phytosterol diversity, reaction mechanism and the nature of the active site. Biochem Soc Trans 33:1189–1196

    Article  PubMed  CAS  Google Scholar 

  22. Mangla A, Nes WD (2000) Sterol C-methyl transferase from Prototheca wickerhamii: mechanism, sterol specificity, and inhibition. Bioorg Med Chem 8:925–936

    Article  PubMed  CAS  Google Scholar 

  23. Nes WD, Song Z, Dennis AL, Zhou W, Nam J, Miller MB (2003) Biosynthesis of phytosterols: kinetic mechanism for the enzymatic C-methylation of sterols. J Biol Chem 278:34505–34516

    Article  PubMed  CAS  Google Scholar 

  24. Nes WD, Le PH (1990) Evidence for separate intermediates in the biosynthesis of 24β-methylsterol end products by Gibberella fujikuroi. Biochim Biophys Acta 1042:119–125

    CAS  Google Scholar 

  25. Nes WD (2003) Enzyme mechanisms for C-methylations. Phytochemistry 64:75–95

    Article  PubMed  CAS  Google Scholar 

  26. Bouvier-Nave P, Husselstein T, Benveniste P (1998) Two families of sterol methyltransferases are involved in the first and the second methylation steps of plant sterol biosynthesis. Eur J Biochem 256:88–96

    Article  PubMed  CAS  Google Scholar 

  27. Nes WD (2000) Sterol methyltransferase: enzymology and inhibition. Biochim Biophys Acta 1529:63–88

    PubMed  CAS  Google Scholar 

  28. Parker SR, Nes WD (1992) Regulation of sterol biosynthesis and phylogenetic implications. Am Chem Soc Symp Ser 497:110–145

    CAS  Google Scholar 

  29. Nes WD, Jayasimha P, Zhou W, Kanagasabai R, Jin C, Jaradat TT, Shaw RW, Bujnicki JM (2004) Sterol methyltransferase: functional analysis of highly conserved residues by site-directed mutagenesis. Biochemistry 43:569–576

    Article  PubMed  CAS  Google Scholar 

  30. Jayasimha P (2006) Sterol methyltransferase: protein engineering, molecular mapping of adomet-binding site. Thermodynamic analysis and its phylogenetic implications. Ph.D. dissertation, Texas Tech University, p 193

  31. Nes WD, Sinha A, Jayasimha P, Zhou W, Song Z, Dennis AL (2006) Probing the sterol binding site of soybean sterol methyltransferase by site-directed mutagenesis: functional analysis of conserved aromatic amino acids in region 1. Arch Biochem Biophys 448:23–30

    Article  PubMed  CAS  Google Scholar 

  32. Zhou W, Nes WD (2003) Sterol methyltransferase 2: purification, properties and inhibition. Arch Biochem Biophys 420:18–34

    Google Scholar 

  33. Venkatramesh M, Guo D, Jia Z, Nes WD (1996) Mechanism and structural requirements for transformation of substrates by the (S)-adenosyl-L methionine: Δ24(25)-sterol methyl transferase from Saccharomyces cerevisiae. Biochim Biophys Acta 1299:313–324

    Google Scholar 

  34. Nes WD, Janssen GG, Bergenstrahle A (1991) Structural requirements for transformation of substrates by the (S)-adenosyl-l-methionine: Δ24(25)-sterol methyl transferase. J Biol Chem 266:15202–15212

    Google Scholar 

  35. Kanagasabai R, Zhou W, Liu J, Nguyen TTM, Veeramachaneni P, Nes WD (2004) Disruption of ergosterol biosynthesis, growth and the morphological transition in Candida albicans by sterol methyltransferase inhibitors containing sulfur at C-25 in the sterol side chain. Lipids 39:737–746

    PubMed  CAS  Google Scholar 

  36. Nes WD, Guo D, Zhou W (1997) Substrate-based inhibitors if the (S)-adenosyl-L-methionine Δ24(25)- to Δ24(28)-sterol methyltransferase from Saccharomyces cerevisiae. Arch Biochem Biophys 342:68–81

    Google Scholar 

  37. Venkatramesh M, Guo D, Harman JG, Nes WD (1996) Sterol specificity of the Saccharomyces cerevisiae ERG6 gene product expressed in Escherchia coli. Lipids 31:373–377

    Article  PubMed  CAS  Google Scholar 

  38. Nes WD, Marshall JA, Jia Z, Jaradat TT, Song Z, Jayasimha P (2002) Active site mapping and substrate channeling in the sterol methyltransferase pathway. J Biol Chem 277:42549–42556

    Article  PubMed  CAS  Google Scholar 

  39. Janssen GG, Nes WD (1992) Structural requirements for transformation of substrates by the S-adenosyl-L-methionine: Δ24(25)-sterol methyltransferase: inhibition of analogs of the transition state coordinate. J Biol Chem 267:25856–25863

    Google Scholar 

  40. Zhou W, Song Z, Liu J, Miller MB, Nes WD (2004) 24-Thiacycloartanol, a potent mechanism-based inactivator of plant sterol methyltransferase. Tetrahedron Lett 45:875–878

    Google Scholar 

  41. Malhotra HC, Nes WR (1971) The mechanism of introduction of alkyl groups at C-24 of sterols, IV. Inhibition by triparanol. J Biol Chem 246:4934–4937

    PubMed  CAS  Google Scholar 

  42. Popják G, Meenan A, Parish EJ, Nes WD (1989) Inhibition of cholesterol synthesis and cell growth by 24(R,S),25-epiminolanosterol and triparanol in cultured rat hepatoma cells. J Biol Chem 264:6230–6238

    PubMed  Google Scholar 

  43. Nes WD, Zhou W, Dennis AL, Li H, Jia Z, Keith RA, Piser TM, Furlong ST (2002) Purification, characterization, and catalytic properties of human sterol 8-isomerase. Biochem J 367:587–599

    Article  PubMed  CAS  Google Scholar 

  44. Ator MA, Schmidt SJ, Adams JL, Dolle RE, Kruse LI, Frey CI, Barone JM (1992) Synthesis, specificity, and antifungal activity of inhibitors of the Candida albicans Δ24-sterol methyltransferase. J Med Chem 35:100–106

    Article  PubMed  CAS  Google Scholar 

  45. Park KS, Kang KC, Kim JH, Adams DJ, Johng TN, Paik YK (1999) Differential inhibitory effects of protoberberines on sterol and chitin biosyntheses in Candida albicans. J Antimicrob Chemother 43:667–674

    Article  PubMed  CAS  Google Scholar 

  46. Kirby TJ, Achor RWP, Perry HO, Winkelmann RK (1962) Cataract formation after triapranol therapy. Arch Opthalmol 68:84–87

    Google Scholar 

  47. Kusano G, Takahashi A, Sugiyama K, Nozoe S (1987) Antifungal properties of solanum alkaloids. Chem Pharm Bull 35:4862–4867

    PubMed  CAS  Google Scholar 

  48. Barrett-Bee K, Ryder N (1992) Biochemical apsects of ergosterol biosynthesis inhibition. In: Sutcliffe J, Georgopapadakou NH (eds) Emerging targets and antifungal therapy. Routledge, Chapman and Hall, New York, pp 410–436

    Google Scholar 

  49. Roddick JG (1987) Antifungal activity of plant steroids. Am Chem Soc Symp Ser 325:286–303

    CAS  Google Scholar 

  50. Keeler RF (1984) Mammalian teratogenicity of steroidal alkaloids. In: Nes WD, Fuller G, Tsai L (eds) Isopentenoids in plants: biochemistry and function. Marcel Dekker, New York, pp 531–562

  51. Song Z, Zhou W, Liu J, Nes WD (2004) Mechanism-based active site modification of the soybean sterol methyltransferase by 26,27-dehydrocycloartenol. Bioorg Med Chem Lett 14:33–36

    Article  PubMed  CAS  Google Scholar 

  52. Zhou W, Song Z, Kanagasabai R, Liu J, Jayasimha P, Sinha A, Veeramachanemi P, Miller MB, Nes WD (2004) Mechanism-based enzyme inactivators of phytosterol biosynthesis. Molecules 9:185–203

    Article  CAS  PubMed  Google Scholar 

  53. Nes WD, Marshall JA, Zhou W, He L, Dennis AL (1998) Mechanism-based site modification of sterol methyltransferase by tritium-labeled 26-homocholesta-8,14,26-yn-3β-ol. Tetrahedron Lett 39:8575–8578

    Article  CAS  Google Scholar 

  54. Ator MA, Schmidt SJ, Adams JL, Dolle RE (1989) Mechanism and inhibition of delta 24-sterol methyltransferase from Candida albicans and Candida tropicalis. Biochemistry 28:9633–9640

    Article  PubMed  CAS  Google Scholar 

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Acknowledgments

One of us (WDN) thanks his students and post-doctoral fellows that participated in the synthesis and testing of the compounds described here and cited in the references. The work was supported by a Welch Foundation Grant (-D−1276), a National Science Foundation Grant (MCB-0417436) and a National Institutes of Health Grant (GM63477).

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Correspondence to W. David Nes.

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Song, Z., Nes, W.D. Sterol Biosynthesis Inhibitors: Potential for Transition State Analogs and Mechanism-Based Inactivators Targeted at Sterol Methyltransferase. Lipids 42, 15–33 (2007). https://doi.org/10.1007/s11745-006-3017-1

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  • DOI: https://doi.org/10.1007/s11745-006-3017-1

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