EVIDENCE FOR THE PRESENCE OF METABOLIC STEROLS IN PNEUMOCYSTIS - IDENTIFICATION AND INITIAL CHARACTERIZATION OF PNEUMOCYSTIS-CARINII STEROLS

被引:60
作者
KANESHIRO, ES
ELLIS, JE
JAYASIMHULU, K
BEACH, DH
机构
[1] UNIV CINCINNATI,COLL MED,DEPT ENVIRONM HLTH,CINCINNATI,OH 45267
[2] SUNY HLTH SCI CTR,DEPT MICROBIOL & IMMUNOL,SYRACUSE,NY 13210
关键词
CHOLESTEROL; C-28; STEROLS; C-29; GAS-LIQUID CHROMATOGRAPHY; MASS SPECTROMETRY; STERYL ESTERS; STIGMAST-7-ENOL; STIGMASTA-DIENOL;
D O I
10.1111/j.1550-7408.1994.tb05938.x
中图分类号
Q93 [微生物学];
学科分类号
071005 ; 100705 ;
摘要
Mixed life cycle stages of rat-derived Pneumocystis carinii were isolated from host lungs and their sterols were compared with those present in lungs from normal and immunosuppressed uninfected rats. Gas-liquid chromatography consistently detected, resolved, and quantified 9, 10, and 20 sterol components in the total nonsaponifiable neutral lipid fraction of lungs from normal rats, lungs from immunosuppressed uninfected rats, and P. carinii preparations, respectively. In all samples, cholesterol was the most abundant sterol present, comprising 97%, 93%, and 78% of total sterols in lungs from normal rats, lungs from immunosuppressed uninfected rats, and P. carinii, respectively. Tentative identifications of several rat lung and P. carinii minor sterols were made based on gas-liquid chromatogram retention times and fragmentation patterns from mass spectral analyses. Campesterol (ergost-5-en-3-ol), cholest-5-en-3-one, and beta-sitosterol (stigmast-5-en-3-ol) were among the minor components present in both types of lung controls, and were also components of P. carinii sterols. In contrast to lung controls, the sterols of P. carinii were enriched in C-28 and C-29 sterols with one or two double bonds, and a hydroxyl group at C-3 (ergost-5-en-3-ol, ergost-7-en-3-ol, ergosta-dien-3-ol, stigmast-5-en-3-oI, stigmast-7en-3-ol and stigmasta-dien-3-ol). Steryl esters of P. carinii, probably stored in cytoplasmic lipid droplets, were dominated by those present in the host lung. In separate studies, 3-hydroxy-3-methylglutaryl coenzyme A activity, a key enzyme in the regulation of sterol biosynthesis, was detected in purified P. carinii preparations and incorporation of radiolabeled squalene and mevalonate was observed. Together, these results suggest that the parasite readily takes up and incorporates host sterols, and that the organism synthesizes some of its own ''metabolic sterols.''
引用
收藏
页码:78 / 85
页数:8
相关论文
共 20 条
  • [11] KANESHIRO ES, 1993, PNEUMOCYSTIS CARINII, P45
  • [12] KING RJ, 1982, J APPL PHYSIOL, V53, P1
  • [13] STUDIES ON TETRAHYMENA MEMBRANES - MODIFICATION OF SURFACE MEMBRANE LIPIDS BY REPLACEMENT OF TETRAHYMANOL BY EXOGENOUS ERGOSTEROL IN TETRAHYMENA-PYRIFORMIS
    NOZAWA, Y
    FUKUSHIMA, H
    IIDA, H
    [J]. BIOCHIMICA ET BIOPHYSICA ACTA, 1975, 406 (02) : 248 - 263
  • [14] STRUCTURAL AND PHYSIOLOGICAL FEATURES OF STEROLS NECESSARY TO SATISFY BULK MEMBRANE AND SPARKING REQUIREMENTS IN YEAST STEROL AUXOTROPHS
    RODRIGUEZ, RJ
    PARKS, LW
    [J]. ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1983, 225 (02) : 861 - 871
  • [15] PNEUMOCYSTIS-CARINII SHOWS DNA HOMOLOGY WITH THE USTOMYCETOUS RED YEAST FUNGI
    WAKEFIELD, AE
    PETERS, SE
    BANERJI, S
    BRIDGE, PD
    HALL, GS
    HAWKSWORTH, DL
    GUIVER, LA
    ALLEN, AG
    HOPKIN, JM
    [J]. MOLECULAR MICROBIOLOGY, 1992, 6 (14) : 1903 - 1911
  • [16] WALZER PD, 1993, PNEUMOCYSTIS CARINII, P511
  • [17] Weete J.D., 1980, LIPID BIOCH FUNGI OT
  • [18] YOSHIDA Y, 1989, J PROTOZOOL, V36, P53
  • [19] YOSHIKAWA H, 1988, INT J PARASITOL, V18, P39, DOI 10.1016/0020-7519(88)90034-3
  • [20] FREEZE-FRACTURE LOCALIZATION OF FILIPIN-STEROL COMPLEXES IN PLASMA-MEMBRANES AND CYTO-MEMBRANES OF PNEUMOCYSTIS-CARINII
    YOSHIKAWA, H
    MORIOKA, H
    YOSHIDA, Y
    [J]. JOURNAL OF PROTOZOOLOGY, 1987, 34 (02): : 131 - 137