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以PDF为靶点的新药筛选及活性组分的分离纯化、结构鉴定与活性研究
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摘要
随着抗生素的广泛使用甚至滥用,各种耐药病原菌大量出现,目前临床耐药菌的发展势态已对人类健康构成极大的威胁。寻找新的作用靶点,研发新型抗耐药菌的药物已成为本世纪全球关注的研究热点之一。肽脱甲酰基酶(peptide deformylase,PDF)是原核生物蛋白成熟过程中的一个关键酶,而非真核生物所必需。鉴于PDF具有作为药物筛选靶点的众多优点,近年来被广泛认同为最理想的新一代广谱抗菌药物筛选分子靶点之一。
     本研究采用分子生物学的方法与技术对屎肠球菌(E.faecium)的PDF酶进行克隆表达,用Ni~(2+)金属螯合亲和层析柱对目的蛋白进行分离纯化,对纯化所得PDF进行Western blotting鉴定与活性检测。
     以纯化的PDF为靶点开展了抑酶活性物质筛选和以E.faecium为检定菌的抑菌活性物质筛选。通过对20261个微生物发酵样品的初筛和对初筛阳性样品的两次复筛,获得6株发酵产物活性稳定的阳性菌株,其中游动放线菌103A-00723和游动放线菌103A-08772的发酵产物对多种G~+耐药细菌有抑菌活性,包括MRSA、MRSE、E.faecalis HH22(含双功能修饰酶的粪肠球菌)和VRE。经分类鉴定,这两株菌为游动放线菌属的两个新种,分别被命名为Actinoplanes sichuanensis sp.nov.和Actinoplanes Xinjiangensis sp.nov.。链霉菌I06A-01113的发酵产物抗VRE和S.aureus(金黄色葡萄球菌)的敏感株,但不抗MRSA。
     对获得的阳性菌株I03A-00723进行放大发酵,并对发酵产物进行分离纯化,得到95-1、95-1-h1、95-2、95-3、135、205-1、205-2和205-3八个单一组分,经结构分析95-1、95-2、135、205-1分别被确定为N~b-乙酰色胺、大豆苷元、染料木素和腺苷,95-1-h1、95-3、205-2和205-3因量太少,其结构有待进一步鉴定。本研究首次从游动放线菌中分离得到N~b-乙酰色胺、大豆苷元和染料木素,并首次发现这三个活性物质对PDF酶有抑制作用,而且对E.faecium有抗菌活性,且大豆苷元和染料木素对VRE的抗菌活性优于阳性对照Actinonin。含量极少的组分95-3对VRE的抗菌活性优于Actinonin和已报道的阳性化合物BB3497和VRC3375,与已进入临床研究的阳性化合物LBM415的抗菌活性相当,是值得深入研究的组分。
     本研究还以PDF的晶体结构为基础,采用sybyl7.3软件中的Surflex-Dock对我室Microbial Natural Products Database(微生物天然产物库)进行了虚拟筛选,对部分虚拟筛选阳性化合物进行了抑酶和抗菌活性检测。结果发现,虚拟筛选获得的阳性化合物Polyoxin B、Spergualin和L-4-oxalysine具有一定的抑酶和抗菌活性。同时,对实物筛选获得的阳性化合物和已知阳性抑制剂(Actinonin、LBM415、BB83698、VRC4307、VRC3375和BB3497)与PDF进行分子了对接,发现阳性化合物95-2、135和已知阳性抑制剂的虚拟筛选得分和它们的抑酶和抗菌活性相一致。
     本研究采用实物筛选与虚拟筛选相结合的方法,得到若干活性化合物,为寻找以PDF为靶点的新药或其先导化合物奠定了基础。
With the incorrect use of antibiotics or even abuse,the rapid emergence of various G~+ resistant bacteria,such as MRSA,MRSE,VRE,presents a very serious threat to public health.Therefore,searching for new targets and developing new drugs with novel mechanisms and potent activity against G~+ resistant bacteria have become an urgent need and an international research project.Peptide deformylase(PDF) is an essential enzyme in the protein maturation of prokaryote,but it is absent from mammalian cells.As its many advantages as a drug target,in recent years,PDF has been widely regarded as one of ideal targets for the screening of new broad-spectrum antibiotic agents.
     In this study,PDF of E.faecium was cloned and expressed adopting the methods and techniques of molecular biology.The protein obtained was purified by Ni~(2+) metal chelating affinity chromatography column and was identified by Western blotting and activity assay.
     The screening targeted on PDF includes two parts:screening for inhibiters against E. faecium and screening for inhibiters against PDF activity.As a result,6 positive strains w -ith stable fermentation broths activity were picked out through the initial screening of 20,261 samples of microbial fermentation broths and the other twice re-screening of positive samples.Among them,fermentation broths of positive strains I03A-00723 and I03A-08772 which were identified as nova species of Actinoplanes and named as Aactinoplanes sichuanensis sp.nov,and Actinoplanes xinjiangensis sp.nov,respectively have antimicrobial activity against G~+ resistant bacteria including MRSA,MRSE,E. faecalis HH22 and VRE.The fermentation broth of positive strain I06A-01113 which belongs to streptomyces has antimicrobial activity against VRE not MRSA.
     The positive strain I03A-00723 was fermented largely,its fermentation broth was isolated and active components were purified.As a result,8 components were obtained which were 95-1,95-1-h1,95-2,95-3,135,205-1,205-2 and 205-3.Among them,95-1, 95-2,135 and 205-1 were identified as N~b-acetyltryptamine,daidzein,genistein and adenosine respectively and 95-1-h1,95-3,205-2 and 205-3 haven't been identified because of a little content of their samples.It was the first time that N~b-acetyltryptamine, daidzein and genistein were discovered to be produced by strain of Actinoplanes and to have inhibitory activity not only to enzyme PDF but also to E.faecium.Furthermore,the activity of daidzein and genistein against VRE are superior to a known PDF inhibitor Actinonin,and the activity of the minimal component 95-3 against VRE is superior to positive compounds BB3497 and VRC3375 and is approximate to LBM415 which has been in a stage of clinical study,therefore 95-3 is worthy to be studied further.
     Virtual screening was done with Surflex-Dock in the syby17.3 software on Microbial Natural Products Database,based on the crystal structure of PDF.Some virtual screening compounds were tested the inhibitory activity to PDF and the antibacterial activity to E.faecium.As a result,PolyoxinB,Spergualin and L-4-oxalysine were discovered to have inhibitory activity to PDF and E.faecium.Meanwhile,positive components 95-1,95-2, 135 and known positive compounds such as Actinonin,LBM415,BB83698,VRC4307, VRC3375 and BB3497 were docked with PDF crystal structure,the results showed that their virtual screening scores are correspond to their activities to PDF and E.faecium.
     In this study,several active compounds inhibiting PDF were obtained by applying model screening combining with virtual screening and the research results would lay foundation for finding inhibitors or lead compounds targeted on PDF.
引文
[1]Dan Ferber.Infectious Disease:New Weapons in the Battle of the Bugs[J].Science,2002,18(295):433-434.
    [2]Adams,J.M.J.On the release of the formyl group from nascent protein[J].Mol.Bi-ol.1968,33(3),571-589.
    [3]Meinnel.T,Blnaquet.S.Evidence that Peptide deformylase and methionyl-tRNA (f-Met)Formyltransferase are encoded within the same opeorn in Escherichia coli[J].J Bacterid,1993,175:7737-7740.
    [4]Meinnel T,Blanquet S,Dardel FA.A new subclass of the zinc metalloproteases sup-erfamily revealed by the solution structure of peptide deformylase[J].J Mol Biol.1996,262(3):375-386.
    [5]Rajagopalan,P.T.P.,Yu,X.C,Pei,D.H..Peptide deformylase:A New Type of Mon-onuclearIornProtein[J].J.Am.Chem.Soc.1997,119:12418-12419.
    [6]Chan,M.K.,Gong,W.M.,Rajagopalna,.P.T.R.,et al.Crystal Structure of the Esch-erichia coli Peptide deformylase[J].Biochemistry,1997,36:13904-13909.
    [7]Groche,D.,Becker,A.,Schlichting,l.,et.al..Isolation and crystallization of functio-nally competent E.Coli.Peptide deformylase forms containing either iron or nickel in the active site[J].Biohcem Biophys Res Commun,1998,246:342-346.
    [8]Rajagopalan,P.T.P.,Grimme,S.,Pei,D.Characterization of cobalt(II)-substitute peptide deformylase:Function of the metal ion and the catalyic residue Glu-133[J].Biochemistry,2000,39:779-790.
    [9]Zhou Z,Song X,Gong W.Novel conformational states of peptide deformylase fro-m pathogenic bacterium Leptospira interrogans:implications for population shift[J].J Biol Chem.2005,280(51):42391-42396.
    [10]Clements JM,Ayscough AP,Keavey K,et al.Peptide deformylase inhibitors,poten-tial for a new class of broad spectrum antibacterials[J].Curr Med Chem Anti Infect-ive Agents,2002,1(3):239-249.
    [11]Gilione C,Pierre M,and Meinnel T.Peptide deformylase as a target for new generat-ion,broad spectrum antimicrobial agents[J].Molecular microbiology,2000,36(6):1197-1205.
    [12]Yuan ZY,Trias J,White RJ.Deformylase as a novel antibacterial target[J].Drug Di-scov.Today,2001,6(18):954-961.
    [13]AdrienBoularot,CarmelaGiglione,SylvainPetit,et al.Discovery and Refinement of a New Structural Class of Potent Peptide Deformylase Inhibitors[J].J.Med.Chem.2007,50,10-20.
    [14]Eric T.Baldwin,Melissa S.Harris,Martin R.Deibel et al..Crystal structure of type II peptide deformylase from StapHylococcus aureus[J].J.Biological chemistry,2002,277(34):31163-31171.
    [15]Meinnel T,Christine Lazennec,and Sylvain Blanquet,et al.Structure-function relatio-nships within the peptide deformylase family.Evidence for a conserved architectu-re of the active site involving three conserved motif and a metal ion[J].J.Mol.Biol,1997,267:749-761.
    [16]Becker A,Schlichting I,Kabsch W,et al.Structure of peptide deformylase and ident-ification of the substrate binding site[J].J.Biological Chemistry,1998,273(19):11413-11416.
    [17]Hu XB,Nguyen KT,Jiang VC,et al.Structure-based design of a macrocyclic inhi-bitor for peptide deformylase[J].J Med Chem,2003,46(18):3771-3774.
    [18]Dardel F,Ragusa S,Lazennec C,Blanquet S,Meinnel T.Solution structure of nick-el-peptide deformylase[J].J Mol Biol.1998,280(3):501-513.
    [19]Jain R,Hao B,Liu RP,Chan MK.Structures of E.coli peptide deformylase bound to formate:insight into the preference for Fe~(2+) over Zn~(2+) as the active site metal[J].J Am Chem Soc.2005,127(13):4558-4559.
    [20]Ragusa S.,Mouchet P.,Lazennec C,et al..Substrate recognition and selectivity of peptide deformylase:Similarities and differences with metzincins and thermolysin[J].J.Mol.Biol.1999,289:1445-1457.
    [21]Hackbarth,C.J.,Chen,D.Z.,Lewis,J.G,et al.N-Alkyl Urea Hydroxamic Acids as a New Class of Peptide Deformylase Inhibitors with Antibacetrial Activity[J].Antimi-crob.Agents.Chemother,2002,46(9):2752-2764.
    [22]Lee,M.D.,Antczak,C.,Li,Y.,et al.A new human peptide deformylase inhibitable by actinonin[J].Biochem.Biophys.Res.Commun.,2003,312:309-315.
    [23]Lee,M.D.,She,Y.,Soskis,M.J.,et al.Human mitochondrial peptidede formylase,a new anticancer Target of actinonin-based antibiotics[J].J.Clin.Invest.,2004,114:1107-1116.
    [24]Sindy Escobar-Alvarez,Yehuda Goldgur,Guangli Yang,et al.Structure and Activ-ity of Human Mitochondrial Peptide Deformylase,a Novel Cancer Target[J].J.Mol.Biol.,2009(in press).
    [25]D.Chen,C.Hackbarth,Z.J.Ni,et al.Peptide Deformylase Inhibitors as Antibacter -ial Agents:Identification of VRC3375,a Proline-3-Alkylsuccinyl Hydroxamate Derivative,by Using an Integrated Combinator-ial and Medicinal Chemistry Appro-ach[J].Antimicrobial Agents and Chemotherapy.2004,48(1):250-261.
    [26]Clements J.M.,Beckett R.P.,Brown A.,et al.Antibiotic activity and characterizati-on of BB-3497,a novel peptide deformylase inhibitor[J].Antimicrobial Agents and Chemotherapy,2001,45(2):563-570.
    [27]Molteni V,He XH,Nabakka J,et al.Identification of novel potent bicyclic peptide deformylase inhibitors[J].Bioorg Med Chem Lett,2004,14(6):1477-1481.
    [28]Johnson K W,Lofland D,Moser H E.PDF inhibitors:An emerging class of antiba-cterial drugs[J].Curr Drug Targets Infect Disord,2005,5(1):39-52.
    [29]Yoo J S,Zheng C J,Lee S,et al.Macrolactin N,a new peptide deformylase inhibi-tor produced by Bacillus subtilis[J].Bioorg Med Chem Lett,2006,16(18):4889-4892.
    [30]Watters A A,Jones R N,Leeds J A,et al.Antimicrobial activity of a novel peptide deformylase inhibitor,LBM415,tested against respiratory tract and cutaneous infect-ion pathogens:a global surveillance report (2003-2004)[J].Journal of Antimicrobi-al Chemotherapy,2006,57:914-923.
    [31]Chen DZ,Patel DV,Hackbarth CJ,et al.Actinonin,a naturally occuring antibact-erial agent,is a potent deformylase inhibitor[J].Biochemistry,2000,39(6):1256-1262.
    [32]Guilloteau JP,Mathieu M,Giglione C,et al.The crystal structures of four peptide deformylases bound to the antibiotic actinonin reveal two distinct types:a platform for the structure-based design of antibacterial agents[J].J Mol Biol,2002,320(5):951-962.
    [33]Boularot A,Giglione C,Artaud I,et al.Structure-activity relationship analysis and therapeutic potential of peptide deformylase inhibitors[J].Curr Opin Invest Drugs,2004,5(8):809-822.
    [34]Thomas R.Fritsche,Helio S.Sader,Roy Cleeland,et al.Comparative Antimicrobial Characterization of LBM415(NVP PDF-713),a New Peptide Deformylase Inhibitor of Clinical Importance[J].ANTIMICROBIAL AGENTS AND CHEMOTHERAPY,2005,49(4):1468-1476.
    [35]Lofland D,Difuntorum S,Waller A,et al.In vitro antibacterial activity of the pepti-de deformylase inhibitor BB-83698[J].Antimicrob Chemother,2004,53(4):664-666.
    -
    [36]Meinnel T,Patiny L,Ragusa S,et al.Design and synthesis of substrate analog inh -ibitors of peptide deformylase[J].Biochemistry,1999,8(14):4287-4295.
    [37]Durand DJ,Gordon G,Barbara C,et al.Peptide aldehyde inhibitors of bacterial pep -tide deformylases[J].Arch Biochem Biophys,1999,367(2):297-302.
    [38]Chu M,Mierzwa R,He L,et al.Isolation and structure elucidation of two novel def -ormylase inhibitors produced by Streptomyces sp[J].Tetrahedron Lett,2001,42(21):3549-3551.
    [39]Hao B,Gong WM,Rajagopalan PT,et al.Structural basis for the design of antibiot -ics targeting peptide deformylase[J].Biochemistry,1999,38(15):4712-4719.
    [40]Hu XB,Nguyen KT,Jiang VC,et al.Macrocyclic inhibitors for peptide deformyla -se:a structure-activity relationship study of the ring size[J].J Med Chem,2004,47(20):4941-4949.
    [41]Chang-Ji Zheng,Sangku Lee,Choong-Hwan Lee,et al.Macrolactins O-R,Glycosyl -ated 24-Membere Lactones from Bacillus sp.AH159-1[J].J.Nat.Prod.2007,70:1632-1635.
    [42]Apfel C,Banner DW,Bur D,et al.2-(2-oxo-1,4-dihydro-2H-qui nazolin-3-yl)-and 2-(2,2-dioxo-1,4-dihydro-2:H-2 λ 6-benzo[1,2,6]thiadiazin-3-yl)-N-hydr -oxy-acetamides as potent and selective peptide deformylase inhibitors[J].J Med Chem,2001,44(12):1847-1852.
    [43]Yun-Ju Kwon,Mi-Jin Sohn,Chang-Ji Zheng,et al.Fumimycin:A Peptide Deform ylase Inhibitor with an Unusual Skeleton Produced by Aspergillus fumisynnematus [J].Org.Lett.,2007,9(13):2449-2451.
    [44]Credito K.,Lin G.,Ednie L.M.,et al.Antistaphylococcal activity of LBM415,a ne -w peptide deformylase inhibitor,compar -ed with those of other agents[J].Antimicr -ob.Agents Chemother,2004,48(10):4033-4036.
    [45]Ednie,L.M.,Pankuch,G.,and Appelbaum,P.C.Antipneumococcal activity of LBM-15,a new peptide deformylase inhibitor,compared with those of other agents.Antimicrob.Agents Chemother.,2004,48(10):4027-4032.
    [46]Neckermann G.,Yu D.,Mann I.K.,et al.LBM415,a new oral peptide deformylase inhibitor:Efficacy in murine infection models[C].44 th Intersci Conf Antimicrob Agents Chemother(Oct 30-Nov2,Washington DC) 2004.Abst F-1964.
    [47]East SP,Beckett RP,Brookings DC,et al.Peptide deformylase inhibitors with act -ivity against respiratory tract pathogens[J].Bioorg Med Chem Lett,2004,14(1):59-62.
    [48]Wise R.,Andrews J.M.,Ashby J..In Vitro Activities of Peptide Deformylas Inhibit-ors against Gram-Positive Pathogens[J].ANTIMICROBIAL AGENTS AND CHE-MOTHERAPY,2002,46(4):1117-1118.
    [49]Bowker KE,Noel AR,MacGowan AP.In vitro activities of nine peptide deformyl-ase inhibitors and five comparator agents against respiratory and skin pathogens[J].Int J Antimicrob Agent,2003,22(6):557-561.
    [50]Huntington KM,Yi T,Wei Y,et.al.Synthesis and Antibacetrial Activity of Peptide Deformylase Inhibiotsr[J].Biochemistry,2000,39(15):4543-4551.
    [51]Smith,H.K.,Beckett,R.P.,Clements,J.M.,et al.Structure Activity Relationships of the Peptide Deformylase Inhibitor BB-3497:Modication of the Metal Binding Group[J].Bioorg.Med.Chem.Lett,2002,12:3595-3599.
    [52]Madison V,Duca J,Bennett F,et al.Binding affinities and geometries of various metal ligands in peptide deformylase inhibitors[J].Biophys Chem,2002,101-102:239-247.
    [53]Jain R,Sundram A,Lopez S,et al.a-substituted hydroxamic acids as novel bacteri-al deformylase inhibitor-based antibacterial agents[J].Bioorg Med Chem Lett,2003,13(23):4223-4228.
    [54]Davies SD,Ayscough AP,Bechett RP,et al.Structure-activity relationships of th-e peptide deformylase inhibitor BB-3497 modification of the methylene spacer and the PI' side chain[J].Bioorg Med Chem Lett,2003,13(16):2709-2713.
    [55]Davies SJ,Ayscough AP,Beckett RP,et al.Structure-activity relationships of the peptide deformylase inhibitor BB-3497:modification of the P2' and P3' side chain-s[J].Bioorg Med Chem Lett,2003,13(16):2715-2718.

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