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Volatile components and nutritional qualities of Viscum articulatum Burm.f. parasitic on ancient tea trees

fOOD SCIENCE & NUTRITION 2019年第9期7卷 3017-3029页

作者： Wang, Qiushuang Chen, Dong Zhang, Qianwen Qin, Dandan Jiang, Xiaohui Li, Hongjian fang, Kaixing Cao, Junxi Wu, Hualing Guangdong Acad Agr Sci Tea Res Inst Guangdong Key Lab Tea Plant Resources Innovat & U Guangzhou Guangdong Peoples R China Mississippi State Univ Dept Plant & Soil Sci Starkville MS USA

Volatile flavor compounds (VfCs) and nutrients in Viscum articulatum Burm.f. parasitic on ancient tea trees (named TM) were studied in this research by headspace solid-phase microextraction (HS-SPME)/gas chromatography-mass spectrometry (GC-MS) and conventional methods. Sixty-six volatile compounds belonging to different classes were identified by GC-MS. The ketones, alcohols, and aldehydes were the principal aroma groups in TM according to principle component analysis (PCA). The most abundant aroma components in TM included benzaldehyde (9.64%), geranylacetone (7.92%), epoxy-beta-ionone (7.71%), beta-linalool (7.35%), methyl salicylate (6.96%), and hotrienol (6.14%), significantly higher than CKs (p < .05). The positive PC1 and PC2 in TM were correlated with benzaldehyde, hotrienol, methyl salicylate, and geranylacetone. The mistletoes could be differentiated from CKs due to the difference in aroma compounds. Clean and fresh, woody and nutty odor with minor floral scent was the characteristics of TM. Analysis of the nutritional components showed that contents of polyphenols and catechins in TM were at trace levels, significantly lower than CKs (p < .05). The total contents of polyphenols, amino acids, carbohydrates, and caffeine in TM were significantly lower from the total soluble solids (p < .05), indicating that there were still lots of compounds undetected in TM. The sensory test showed that the taste and aroma in TM can be accepted, which indicates TM could be developed into alternative tea drinks in the future.

关键词： aroma nutrients Viscum articulatum Burm f

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ALPHA,BETA-BIDENTATE CRADP ABOLISHES THE NEGATIVE COOPERATIVITY Of YEAST MITOCHONDRIAL f1-ATPASE

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BIOCHIMICA ET BIOPHYSICA ACTA 1985年第1期806卷 35-41页

作者： WIEKER, HJ HESS, B Max-Planck-Institut für Ernährungsphysiologie Rheinlanddamm 201 D-4600 Dortmund 1 F.R.G.

The hydrolysis of MgATP and MgITP by mitochondrial f1-ATPase from S. cerevisiae was competitively inhibited by .alpha.,b-CrADP, .alpha.,.beta.,.gamma.-CrATP and .beta.,.gamma.-CrATP. The apparent K''i values of the 3 complexes are in the range of the 1/2-saturating MgATP concentration. The negative cooperativity (nH = 0.7) of MgATP hydrolysis was totally abolished by .alpha.,.beta.-CrADP (nH = 1.0), while it was not affected by the CrATP. It is concluded that .alpha.,.beta.-CrADP binds exclusively at the regulatory site and that CrATP binds exclusively to the catalytic site.

关键词： f 1 -ATPase kinetics Chromium-nucleotide complex (Yeast mitochondria) Hepes 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid Mes 4-morpholineethanesulfonic acid CD circular dichroism

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SPATIAL-ORGANIZATION Of THE CYTOCHROME B6-f COMPLEX WITHIN CHLOROPLAST THYLAKOID MEMBRANES

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BIOCHIMICA ET BIOPHYSICA ACTA 1986年第1期849卷 94-103页

作者： ALLRED, DR STAEHELIN, LA UNIV COLORADO DEPT MOLEC CELLULAR & DEV BIOL BOULDER CO 80309 USA

The spatial distribution of the chloroplast thylakoid protein complex of cytochromes f and b-563, and the Rieske iron-sulfur protein (Cyt b6-f) has been controversial because of conflicting results obtained by different techniques. We have combined the following biochemical and immunochemical techniques to approach this question: (1) french press disruption of thylakoids, followed by repeated two-phase aqueous polymer partitioning to separate inside-out grana from right-side-out stroma membrane fragments;(2) electrophoretic analysis followed by the 3,3'',5,5''-tetramethylbenzidine stain for cytochrome hemes;(3) electroblot analysis with anti-Cyt b6-f antibodies;(4) agglutination of membrane fragments with anti-Cyt b6-f antibodies;and (5) post-embedment thin-section immunolabeling of chemically fixed or ultrarapidly frozen chloroplasts with anti-Cyt b6-f antibodies. Our results indicate that the complex is present in both of the isolated membrane fragment populations in similar amounts, with the bulk of the immunoreactive sites exposed to the thylakoidal lumen. Direct immunolabeling of thin-sectioned chloroplasts resulted in localization of the complex throughout the thylakoids, without specialized compartmentation. These results provide both the temporal and spatial resolution necessary for accurate localization of the complex. We concur with models proposing distribution of Cyt b6-f throughout all thylakoid membranes.

关键词： Cytochrome b 6 - f complex Spatial distribution Cf 0 Cf 1 ATP synthase Thylakoid membrane Membrane organization (Pea, Spinach chloroplasts) Cyt cytochrome PS Photosystem TMBZ tetramethylbenzidine Tricine N -[2-hydroxy-1,1-bis(hydroxymethyl)ethyl]-glycine

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THE f1f0-ATPASE Of ESCHERICHIA-COLI - THE SUBSTITUTION Of ALANINE BY TYROSINE AT POSITION 25 IN THE C-SUBUNIT AffECTS fUNCTION BUT NOT ASSEMBLY

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BIOCHIMICA ET BIOPHYSICA ACTA 1989年第2期978卷 299-304页

作者： fIMMEL, AL fORDHAM, SA AUSTRALIAN NATL UNIV DIV SCI DEPT BIOCHEM GPO BOX 4 CANBERRA ACT 2601 AUSTRALIA

A site-directed mutation in the gene which does for the c-subunit of the f1f0-ATPase, resulting in the substitution of Ala-25 by Tyr, has been constructed and characterized. A plasmid carrying the mutation was used to transform strain AN943 (uncE429). The resulting strain is unable to grow on succinate as sole carbon source and possesses an uncoupled growth yield. Membranes prepared from the mutant possess low levels of ATPase activity and are proton-impermeable. The f1-ATPase activity was found to be inhibited by 80% when bound to the membrane. When carried on a plasmid, the mutation is dominant in complementation tests with all mutant unc alleles tested and when transformed into wild-type strain AN346, the mutation results in an uncoupled phenotype. A mutant which overcomes this dominance was isolated and found to possess an 11-amino-acid deletion extending froim Ile-55 to Met-65 within the c-subunit. These results are discussed in relation to the previously isolated Ala-25 to Thr mutant (fimmel, A.L., Jans, D.A., Hatch, L., James, L.B., Gibson, f. and Cox, G.B. (1985) Biochim. Biophys. Acta 808, 252-258) and in relation to a previously proposed model for the f0 (Cox, G.B., fimmel, A.L., Gibson, f. and Hatch, L. (1986) Biochim. Biophys. Acta 849, 62-69).

关键词： c -subunit Site directed mutagenesis Mutagenesis ATPase, f 1 f 0 - ( E. coli ) DCCD dicyclohexylcarbodiimide CCCP carbonylcyanide m -chlorophenylhydrazone

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OXIDATION REDUCTION KINETICS Of CYTOCHROME-f IN WHOLE CELLS

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JOURNAL Of PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1987年第1期1卷 45-60页

作者： MAROTI, P MENDE, D WIESSNER, W UNIV GOTTINGEN INST PFLANZENPHYSIOLEXPTL PHYKOL ABTD-3400 GOTTINGENFED REP GER

The kinetic aspects of the cytochrome f function and its relation to the non-cyclic electron transport were investigated in photosynthetizing green algae under physiological conditions. Easy-to-use and low cost single- and double-beam spectrophotometers were constructed which enabled the measurement of light-induced absorption changes of cytochromes of highly scattering samples under different light—dark preconditioning regimes. The complexity of the light-induced absorption spectra in the 540 – 570 nm spectral range is discussed. The lack of separation of the components based on their kinetic behaviour indicated that different cytochrome f forms contributed to the spectra. By comparison with the time course of the variable part of the fluorescence at 744 nm at room temperature, it was demonstrated that the oxidation of cytochrome f is a pure photochemical process if the half-risetime is greater than 50 ms. The dark-reduction kinetics is monophasic after a single-flash excitation of dark-adapted algae ( t 1 2 = 2 ms) or after producing a photostationary state by means of a long (1 s) and relatively weak (half-risetime of the oxidation greater than 50 ms) flash ( t 1 2 = 500 ms, highly dependent on the systematic position and the states of the algae). The biphasicity (the existence of a mixture of fast and slow components) is evident in the reduction kinetics after excitation by a long and intense flash. The results are discussed within the framework of a simple linear pathway: the electrons from a pool of reduced plastoquinone are transferred to cytochrome f , to plastocyanin and then to the reaction centre of photosystem I. We distinguish basically two states of electron pressure in the plastoquinone pool: high if the half-time of dark reduction is less than 15 ms, and low if it is greater than 100 ms. The states of the pool can interconvert by preconditioning (dark—light regime) and excitation (oxidation). The majority of the data presented in this paper were obta

关键词： Green algae photosynthesis electron transport cytochrome f light—dark redox reactions.

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DISSOCIATION-RECONSTITUTION EXPERIMENTS SUPPORT THE PRESENCE Of 2 CATALYTIC BETA-SUBUNITS IN MITOCHONDRIAL f1

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BIOCHIMICA ET BIOPHYSICA ACTA 1987年第2期894卷 277-283页

作者： NIEBOER, P HARTOG, Af BERDEN, JA UNIV AMSTERDAM BCP JANSEN INST BIOCHEM LABPLANTAGE MUIDERGRACHT 121018 TV AMSTERDAMNETHERLANDS

Mitochondrial f 1 , inactivated to various extents with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl), was dissociated with LiCl and reconstituted after removal of the salt. This procedure resulted in a reactivation that corresponded with a reactivation theoretically expected on the basis of the assumption that the reassociation of β-subunits into native f 1 molecules is random and that two out of the three β-subunits are directly involved in catalysis. Repeated inactivation of such reactivated f 1 , followed by the same dissociation-association procedure, resulted in similar data. After inactivation of f 1 by covalent binding of 2-N-AT(D)P to one catalytic site, no reactivation upon dissociation-reassociation was obtained due to the fact that such modified f 1 did not dissociate under the experimental conditions used.

关键词： ATPase, f 1 - Quaternary structure Chemical modification β-Subunit Catalytic site (Bovine heart mitochondria) NBD-Cl 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (also named 4-chloro-7-nitrobenzofurazan) f 1 mitochondrial ATPase DCCD dicyclohexylcarbodiimide

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ISOLATION Of THE PROTON-TRANSLOCATING f0f1-ATPASE fROM RHODOSPIRILLUM-RUBRUM CHROMATOPHORES, AND ITS fUNCTIONAL RECONSTITUTION INTO PROTEOLIPOSOMES

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BIOCHIMICA ET BIOPHYSICA ACTA 1989年第1期975卷 148-157页

作者： SLOOTEN, L VANDENBRANDEN, S VrijeUniversiteit Brussel Faculty of Sciences Laboratory of Biophysics Brussels (Belgium)

The proton-translocating f0f1-ATPase was isolated from Rhodospirillum rubrum chromatophores by extraction with octyglucoside and deoxycholate, and further purified by sucrose gradient centrifugation. The enzyme was reconstituted into sonicated phospholipid vesicles by incubation with cholate, followed by centrifugation through a Sephadex column. ATP-hydrolysis catalyzed by f0f1-proteoliposomes is accelerated approx. 5-10 fold and approx. 15-20 fold by protonophorous uncouplers during assays with or without sulfite, respectively. Maximal turnover numbers are approx. 320 and 60 mol/s during hydrolysis with or without sulfite. The reconstituted enzyme is in, or close to, the native state with respect to the kinetics and regulation of ATP-hydrolysis. It generates a proton gradient (.***) during ATPase activity, and the proteoliposomes are capable of .***-driven ATP-synthesis. Gradient centrifugation of the reconstituted vesicles results in separation of lipid without f0f1 from proteoliposomes. In the purified proteoliposomes the minimum phospholipid/protein weight ratio is around 3. The distribution profiles of ATPase activity and .***-driven ATP synthesis after gradient centrifugation do not completely overlap. It is inferred that the size of the proteoliposomes decreases slightly with decreasing lipid/protein weight ratios. ATPase-induced 9-aminoacridine fluorescence changes, indicative of the generation of .***, were negative or positive, depending on the absence or presence of fluorescence quenchers in the external solution. The fluorescence changes became more positive when the probe concentration was lowered. The reasons for this are discussed.

关键词： ATP hydrolysis ATP synthesis Coupling factor Proteoliposome Membrane reconstitution ATPase, f 0 f 1 - (R. rubrum) CCCP carbonylcyanide m -chlorophenylhydrazone Hepes 4-(2-hydroxyethyl)-l-piperazineethanesulfonic acid PMSf phenylmethylsulfonylfluoride Mops 4-morpholinepropanesulfonic acid

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ESCHERICHIA-COLI f1 ATPASE IS REVERSIBLY INHIBITED BY INTRASUBUNIT AND INTERSUBUNIT CROSS-LINKING - AN APPROACH TO ASSESS ROTATIONAL CATALYSIS

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BIOCHIMICA ET BIOPHYSICA ACTA 1987年第1期890卷 97-105页

作者： KANDPAL, RP BOYER, PD UNIV CALIF LOS ANGELES DEPT CHEM & BIOCHEM LOS ANGELES CA 90024 USA UNIV CALIF LOS ANGELES INST MOLEC BIOL LOS ANGELES CA 90024 USA

Reaction of the multisubunit f1 ATPase from Escherichia coli (Ef1) with a bifunctional cleavable crosslinker, 3,3''-dithiobis(succinimidylpropionate) (DSP), has been used to explore the possibility that during catalysis a rotational movement of catalytic subunits relative to noncatalytic subunits occurs. The premise is that such rotational catalysis is tenable if intersubunit crosslinking of a major subunit with one of the minor subunits inhibits the enzyme activity and if upon cleavage of the crosslinks, the enzyme regains activity. The results presented in this paper show that crosslinking of about 5-6 reactive groups on Ef1 with DSP is accompanied by a loss of 2/3 of the enzyme activity. Both intra- and intersubunit crosslinks are formed. The most prominent intersubunit crosslinks are those of .gamma. and .delta. subunits with the .alpha. subunit. Nearly complete recovery of activity can be attained by cleaving the disulfide bond in the crosslinker with dithiothreitol. Because the chemical modification of enzyme groups remains after the crosslinker is cleaved, the loss in activity before cleavage can be ascribed to conformational restraints. The results show that catalysis by the Ef1 ATPase is highly sensitive to the restrictions of crosslinking, and are consistent with the view that catalysis is accompanied by appreciable movements of the major subunits with respect to the minor subunits, as suggested for rotational catalysis.

关键词： f 1 -ATPase ATPase crosslinking Rotational catalysis ATPase conformation ( E. coli ) f 1 coupling factor one ATPase Ef 1 ATPase f 1 ATPase from Escherichia coli Mops 4-morpholinepropanesulfonic acid DSP 3,3′-dithiobis(succinimidylpropionate) SDS sodium dodecyl sulfate DMSO dimethylsulfoxide P i inorganic phosphate DTT dithiothreitol

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LACK Of ABILITY Of TRYPSIN-TREATED MITOCHONDRIAL f1-ATPASE TO BIND THE OLIGOMYCIN-SENSITIVITY CONfERRING PROTEIN (OSCP)

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fEBS LETTERS 1983年第1期162卷 5-10页

作者： HUNDAL, T NORLING, B ERNSTER, L Department of Biochemistry Arrhenius Laboratory University of Stockholm S-106 91 Stockholm Sweden

Soluble beef-heart mitochondrial f1-ATPase modified in its alpha-subunit by mild trypsin treatment (alpha'-f1) can no longer bind oligomycin-sensitivity conferring protein (OSCP) but is still capable of binding to f1-depleted submitochondrial particles, giving rise to a maximally oligomycin-sensitive ATPase, provided the particles contain their native complement of OSCP. When OSCP is removed from the particles, alpha'-f1 can still bind to the particles, but added OSCP induces only a low degree of oligomycin sensitivity. The possible role of OSCP in the functional coupling of the catalytic (f1) and H+-translocating (fo) moieties of mitochondrial ATPase is discussed. The results suggest a functional similarity between the OSCP component of mitochondrial ATPase and the delta-subunit of E. coli ATPase, which is in accordance with the structural homology recently found to exist between the two polypeptides.

关键词： Oligomycin-sensitive ATPase f 1 -ATPase f 1 -subunit Oligomycin-sensitivity conferring protein Reconstitution Trypsin digestion f o and f 1 proton-translocating and catalytic moieties of the mitochondrial ATPase system OSCP oligomycin-sensitivity conferring protein f 6 coupling factor 6 SDS sodium dodecyl sulfate

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DIRECT IDENTIfICATION Of THE fLUOROALUMINATE AND fLUOROBERYLLATE SPECIES RESPONSIBLE fOR INHIBITION Of THE MITOCHONDRIAL-f1-ATPASE

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fEBS LETTERS 1989年第1期255卷 47-52页

作者： DUPUIS, A ISSARTEL, JP VIGNAIS, PV Laboratoire de Biochimie LBIO DRF Centre d'Etudes Nucléaires de Grenoble 85X 38041 Grenoble Cedex France

In the presence of ADP, fluoroaluminate and fluoroberyllate inhibit irreversibly the soluble mitochondrial f 1 -ATPase. We report here direct evidence that this inhibition is related to the tight binding of [ 3 H]ADP, beryllium and fluoride to the enzyme. In the case of beryllium-induced inhibition, the stoichiometry of bound species is 1 mol [ 3 H]ADP, 1 mol beryllium and 2 or 3 mol fluoride depending on the initial fluoride concentration used, which indicates that both the combinations ADP 1 ,Be 1 ,f 3 and ADP 1 ,Be 1 ,f 3 are competent for inhibition. In the case of aluminium-induced inhibition, the binding stoichiometry of 4 mol fluoride per mol [ 3 H]ADP favours the following combination of bound species ADP 1 ,Al 1 ,f 4 . These results favour a model where fluorometals mimic phosphate and form an abortive complex with ADP in the catalytic site(s) of f 1 .

关键词： fluoride Beryllium Aluminum ATPase, f 1 - Nucleotide analogue NDP nucleoside diphosphate NTP nucleoside triph. p f , colog of the free fluoride concentration CDTA trans -1,2 diaminocyclohexane- N , N , N ′, N ′-tetraacetic acid

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