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STRUCTURE Of MITOCHONDRIAL CRISTAE MEMBRANES

BIOCHIMICA ET BIOPHYSICA ACTA 1974年第2期344卷 119-155页

作者： HARMON, HJ HALL, JD CRANE, fL PURDUE UNIV DEPT BIOL SCI W LAFAYETTE IN 47907 USA BOSTON BIOMED RES INST DEPT CELL PHYSIOL BOSTON MA 02114 USA

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BENDS IN fISH

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COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY 1974年第2A期49卷 311-&页

作者： DAOUST, BG SMITH, LS VIRGINIA MASON RES CTR SEATTLEWA 98101 UNIV WASHINGTON SEATTLEWA 98101

1. 1. fish mortality due to low-level nitrogen supersaturation in natural waters (as little as 15 per cent) raises the question of their sensitivity to decompression-induced diver's bends. 2. 2. fingerling salmonids ( Salmo gairdnerii and Onchorhynchus kisutch ) have been saturated with air, and normoxic helium and argon at a range of initial pressures ( P i ), ∗ up to 6 atm, and then decompressed through a range of initial/final pressure ( P f ) ratios ( P i / P f ) as high as 8.0. 3. 3. The results clearly show marked differences in bends-producing potential of these different gases with formation of histologically demonstrated tissue bubbles and emphasize the unsuitability of either excess partial pressure (AP) or relative decompression ( P i / P f ) as predictive indices of decompression stress. 4. 4. The results indicate that experimental determination of the critical conditions for bubble formation in blood and tissues in vivo may be possible with such material to a precision not possible in mammalian studies.

关键词： fish respiration bends bubble formation decompression sickness diffusion Salmo gairdnerii Onchorhynchus kisutch ATA atmospheres absolute Δ P initial pressure of equilibration ( P i )—final pressure ( P f ) to which decompression was made synonymous with “excess gas tension” P i / P f relative decompression

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RAT ALPHA-fETOPROTEIN .3. REfINEMENT Of RADIOIMMUNOASSAY fOR DETECTION Of 1 NG RAT ALPHA1f

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IMMUNOCHEMISTRY 1973年第7期10卷 439-442页

作者： SELL, S GORD, D UNIV CALIF SAN DIEGOMED SCHLA JOLLACA 92037

The conditions for a competitive binding radioimmunoassay of rat α 1 -fetoprotein, sensitive and reproducible at the nanogram level, are described. Careful selection of the antiserum dilution and incubation times permits approximately a 10-fold increase in the sensitivity of the radioimmunoassay. The mean serum α 1 f concentration for normal adult male Buffalo rats is 0·026 ± 0·0012 (SEM) μ g/ml.

关键词： α 1 f Rat α 1 -fetoprotein α 1 f ∗ Rat α 1 f labelled with 125 I αMf Rat α-macroglobulin acute phase protein Anti- α 1 f Goat anti-rat α 1 f NRS Normal rat serum NGS Normal goat serum Anti-α-SP Goat anti-adult rat alpha serum proteins SDS Sodium dodecyl sulfate SEM Standard error of the mean IEf Isoelectric focusing

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The interaction between the mitochondrial ATPase (f₁) and the ATPase inhibitor

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BBA - Bioenergetics 1973年第2期292卷 338-349页

作者： Van De Stadt, R.J. De Boer, B.L. Van Dam, K. Laboratory of Biochemistry B. C. P. Jansen Institute Postal address: Plantage Muidergracht 12 Amsterdam The Netherlands. University of Amsterdam Amsterdam The Netherlands

1. The naturally occurring mitochondrial ATPase inhibitor inhibits the mitochondrial ATPase (f1) non-competitively. 2. The interaction between inhibitor and inhibitor-depleted f1 or submitochondrial particles is dimin... 详细信息

1. The naturally occurring mitochondrial ATPase inhibitor inhibits the mitochondrial ATPase (f₁) non-competitively. 2. The interaction between inhibitor and inhibitor-depleted f₁ or submitochondrial particles is diminished when the ratio of ATP/ADP is low or when energy is generated by substrate oxidation. 3. The dissociation of the inhibitor from coupled Mg-ATP particles is promoted when substrates are being oxidized. This results in the appearance of a large uncoupler-stimulated ATPase activity. Activation of the uncoupler-stimulated ATPase activity is also achieved by incubation of the particles with ADP. 4. The ATPase activity of Mg-ATP particles is determined by the turnover capacity of f₁. When endogenous inhibitor is removed, energy dissipation becomes the rate-limiting step. This energy dissipation can be activated by an uncoupler. 5. Evidence is presented for the existence of a non-inhibited intermediate f₁-inhibitor complex. © 1973.

关键词： f 1 mitochondrial ATPase A particles submitochondrial particles prepared by sonication of beef-heart mitochondria in an ammonia solution at pH 9.2 AS particles submitochondrial particles prepared by treatment of A particles with Sephadex G-50 TES N -tris(hydroxymethyl)methyl-2-aminoethanesulphonic acid fCCP carbonyl cyanide p -trifluoromethoxyphenylhydrazone 1799 bis-hexafluoroacetone TMPD N , N , N ′, N ′-tetramethyl- p -phenylenediamine

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IMPROVED ESTIMATION Of BODY MASSES AND TURNOVER Of CHOLESTEROL BY COMPUTERIZED INPUT-OUTPUT ANALYSIS

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JOURNAL Of LIPID RESEARCH 1973年第2期14卷 189-196页

作者： SAMUEL, P LIEBERMAN, S QUEENS HOSP CTR ARTERIOCLEROSIS RES LAB JAMAICA NY 11432 USA CITY UNIV NEW YORK QUEENS COLL DEPT MATH FLUSHING NY 11367 USA ROCKFELLER UNIV NEW YORK NY 10021 USA

In 23 patients, the decay curves of serum cholesterol specific activity after a single intravenous dose of radioactive cholesterol were measured for 16-66 wk and were subjected to computerized input-output analysis. Of 17 patients with decay curves followed for longer than 50 wk, a three-exponential curve fit was better in 12, and a two-exponential curve fit in 5, according to computerized f tests. Of six patients with decay curves followed for less than 50 wk, a two-exponential curve fit was better in five and a three-exponential curve fit in one. In the 13 patients who exhibited three-exponential curve fits, the third exponential appeared after 13-43 wk of observation (average, 25 wk). In 12 patients of this group who were followed for 50 wk or more, turnover rates and exchangeable masses of cholesterol were measured at maximum lengths of the curves (50-66 wk), and these parameters were then compared with measurements made with curves successively shortened down to 10-12 wk. The average differences between analyses of the minimum vs. the maximum lengths of the curves were: It (input rate: absorbed dietary plus biosynthesized cholesterol), 14% larger (1.24 vs. 1.09 g/day); M(a) (rapidly exchangeable mass of cholesterol), no change (34 vs. 33 g); M (total exchangeable mass), 26% smaller (67 vs. 91 g); M - M(a) (remaining exchangeable mass), 39% smaller (40 vs. 65 g). Significant differences in It, M, and M - M(a) (minimum vs. maximum curve lengths) were found in both normolipidemic and hypercholesterolemic patients, and the differences were of similar magnitude in the two groups. Since only 12 of 17 patients followed for 50 wk or longer demonstrated three-exponential curve fits, various means were sought by which it might be predicted at the outset whether a given patient must be studied for so long a time; none was found. However, in the group with two exponentials the value of M(a) was significantly larger than those with three-exponential curve fits, and this dif

关键词： computerized f test multiexponential decay curve fitting hypercholesterolemia coronary artery disease

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INHIBITION Of PROTEIN CHAIN INITIATION IN EUKARYOTES BY DEACYLATED TRANSfER-RNA AND ITS REVERSIBILITY BY SPERMINE

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BIOCHIMICA ET BIOPHYSICA ACTA 1973年第3期324卷 386-396页

作者： KYNER, D ZABOS, P LEVIN, DH INST MUSCLE DIS 515 E 71ST STNEW YORKNY 10021

The eukaryotic 80-S initiation complex, (80-S ribosome complexed with Met-tRNA f and the trinucleotide AUG, 80-S-Met-tRNA f -AUG) is readily assembled at 5 mM MgCl 2 from mouse fibroblast 40-S and 60-S ribosomal subunits, rat liver Met-tRNA f , and AUG. The subunits were prepared and separated in 0.5 M KCl and required no exogenous initiation factors or GTP. formation of the (80-S-Met-tRNA f -AUG) complex as measured by the incorporation of [ 35 S]Met-tRNA f was inhibited by uncharged tRNA. The extent of inhibition was analyzed by three assays: (a) binding of the complex on nitrocellulose membranes, (b) [ 35 S]Met-puromycin synthesis, and (c) sedimentation of the complex in sucrose density gradients. All of the eukaryotic species of tRNA examined were strongly inhibitory; these included partially purified tRNA f Met , tRNA M Met , tRNA Leu , tRNA Phe , and unfractionated tRNA. No selective inhibition was displayed by tRNA f Met . By contrast, amino acyl-tRNA was a poor inhibitor and 18-S rRNA was not inhibitory. Inhibition was proportional to the concentration of uncharged tRNA, but could be reversed by increasing the concentration of Met-tRNA f or ribosomes relative to tRNA. The order of addition was of importance. Preincubation of the ribosomes with uncharged tRNA produced extensive inhibition; conversely, preincubation with Met-tRNA f greatly reduced inhibition. Mg 2+ did not affect the extent of inhibition from 3 to 10 mM. Spermine displayed two functions in this system: (a) it could partially replace Mg 2+ during 80-S complex formation, 3 mM Mg 2+ plus 0.2 mM spermine being as effective as 5 mM Mg 2+ ; and (b) at higher spermine concentrations, inhibition by tRNA was reversed. The addition of Met-tRNA f caused extrusion of uncharged tRNA from ribosomes. The results suggest that tRNA may have a regulatory function of protein chain initiation by interfering with Met-tRNA f binding to the ribosomal P site.

关键词： (80-S-Met-tRNA f -AUG) 80-S ribosome complexed with Met-tRNA f and the trinucleotide AUG

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MODIfICATION Of AffINITY LABELED ANTIBODIES

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IMMUNOCHEMISTRY 1973年第7期10卷 455-460页

作者： HADLER, N METZGER, H NIAMDD ARTHRIT & RHEUMAT BRANCH BETHESDA MD 20014 USA

We previously showed that antibodies which had been affinity labeled at a tyrosyl residue with a diazonium labeling reagent could be further modified usefully. By reductively cleaving the azotyrosine bond, 3-aminotyrosine (3-NH 2 Tyr) was generated in situ , and this residue could then serve as an initiation point for further modifications - for example with the bifunctional reagent difluoro-dinitrobenzene (f 2 DNB). We now present the results of further experiments utilizing this approach. The affinity labeled nitrophenyl binding protein of the plasma cell tumor MOPC 315 was easily reduced with small amounts of dithionite (Na 2 S 2 O 4 ). When f 2 DNB was added it reacted initially at the 3-NH 2 Tyr at position 34 on the light chain and then subsequently with other amino acid residues leading to the formation of light-heavy and intra-light chain cross-links. Although under suitable conditions f 2 DNB also reacted with the native protein of MOPC 315, the reaction occurred largely on the heavy chain. These results testify to the high specificity obtainable using these procedures. Experiments involving the reaction of f 2 DNB with either labeled-unreduced protein, or labeled-reduced protein in the presence of the ligand dinitrophenyl-aminocaproate, suggests that the f 2 DNB may in part have functioned as an affinity labeling reagent. Parallel studies were performed with the phosphorylcholine binding protein of plasma cell tumor TEPC 15. This protein affinity labeled at two alternative tyrosines on the light chains. The azo bonds were much more difficult to reduce wwith dithionite. When they were cleaved some of the sites remained completely inactive whereas others bound normally. The stoichiometry suggests that those sites with a 3-NH 2 Tyr at position 92 were inactivated while those with 3-NH 2 Tyr at position 34 were unaffected. Native protein-15 reacted only minimally with f 2 DNB under the conditions used whereas the labeled-reduced protein became modified on the

关键词： BBS Borate-buffered saline DNP 2, 4-dinitrophenyl f 2 DNB = 1 5-diflioro-2, 4-dinitrobenzene

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COMPARATIVE STUDIES ON PROPERTIES Of EUKARYOTIC PROTEIN-SYNTHESIS INITIATION fACTOR If-1 fROM SEVERAL SOURCES

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BIOCHIMICA ET BIOPHYSICA ACTA 1973年第3期324卷 410-419页

作者： CASHION, LM STANLEY, WM UNIV CALIF SCH BIOL SCIDEPT MOLEC BIOL & BIOCHEMIRVINECA 92664

Eukaryotic protein synthesis initiation factor If-I has been purified from a variety of cells and tissues, and some of the properties of these preparations are compared. If-I activity from all sources elutes close to the excluded volume of Sephadex G-200 columns, indicating similar, if not identical, molecular weights (350 000). There is little or no species or tissue specificity in the binding of the initiator tRNA from one source to If-I purified from another source. The ability of all If-I preparations to form a ternary complex with GTP and the initiator tRNA is inactivated by N- ethylmaleimide ; this sulfhydryl reagent also completely inactivates the rabbit reticulocyte If-I-mediated binding of the initiator tRNA (rabbit liver) to rabbit reticulocyte 40-S ribosomal subunits. Thus, it appears that If-I is an obligatory and ubiquitous protein synthesis initiation factor in the cytoplasm of all eukaryotes.

关键词： Met-tRNA i Met the aminoacylated form of the initiator tRNA in the cytoplasm of eukaryotes fMet-tRNA i Met the N- formylated form of Met-tRNA i Met If-I defined in ref. 2 Met-tRNA f Met ( Escherichia coli ) the aminoacylated (but non -N- formylated ) form of the initiator tRNA in E. coli fMet-tRNA f Met ( E. coli ) the N- formylated form of Met-tRNA f Met ( E. coli )

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INTERSYSTEM EXCITON TRANSfER IN ISOLATED-CHLOROPLASTS

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BIOCHIMICA ET BIOPHYSICA ACTA 1973年第3期325卷 530-538页

作者： BRIANTAIS, JM VERNOTTE, C MOYA, I CNRS LAB PHOTOSYNTH 91190 GIF SUR YVETTE FRANCE

The following arguments in favor of exciton transfer between the two photosystems are presented: 1.(1) MgCl2 (1–10 mM range) decreases the intersystem transfer but does not modify the partition of absorbed photons between the photosystems. MgCl2 addition causes a simultaneous increase of excitation life time (τ) and of fluorescence intensity (f). The same linear relationship is obtained with or without added Mg2+. 2.(2) The deactivation of Photosystem II by the Photosystem II to Photosystem I transfer increases with the level of reduced Photosystem II traps. When all Photosystem II traps are closed, half of Photosystem II excitons are deactivated by transfer to Photosystem I. 3.(3) from the relative values of the 685-nm fluorescence yield and System II electron transport rate in limiting light, measured with and without MgCl2, the values of rate constants of Photosystem II deactivation were calculated. 4.(4) The intersystem transfer determines a 715-nm variable fluorescence, which is lowered by MgCl2 addition. When this transfer is decreased by MgCl2 the efficiency of the transfer between Photosystem II-connected units is enhanced, and a more sigmoidal fluorescence rise is obtained. A double-layer model of the thylakoid membrane where each photosystem is restricted to one leaflet is proposed to explain the decrease of the intersystem transfer after adding cations. It is suggested that MgCl2 decreases the thickness of the Photosystem I polar region, increasing the distance between the pigments of the two photosystems.

关键词： DCMU 3-(3 4-dichlorophenyl)-1 1-dimethylurea f fluorescence intensity τ excitation lifetime

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CHRONOPOTENTIOMETRIC STUDY Of OXIDATION Of SOME DILUTED AMALGAMS IN PRESENCE Of TRACES Of OXYGEN DISSOLVED IN AQUEOUS-SOLUTION .2. STUDY Of INfLUENCE Of VARIOUS PARAMETERS ON REACTION-RATE

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JOURNAL Of ELECTROANALYTICAL CHEMISTRY 1973年第2期43卷 185-195页

作者： BUffLE, J PELLETIE.M MONNIER, D UNIV GENEVA DEPT CHIM MINERALE & ANALSECT CHIM SCIGENEVA 1211SWITZERLAND

The behaviour of dilute amalgams in the presence of trace amounts of dissolved oxygen in aqueous solution has been studied. The diffusion of oxygen in the solution and that of metal in the amalgam seem to be the factors which determine the rates of oxidation of Zn, Cd, Pb and Tl amalgams. The variation of metal concentration in a drop of amalgam with time of contact with traces of dissolved oxygen has been treated mathematically. The influence of different parameters was studied experimentally and these are in accordance with the proposed equation. A simple relation between the rate of oxidation and the amount of oxygen in the solution was found and this can be used for the determination of traces of oxygen in solution.

关键词： A area of the drop (cm 2 ) C O 2 ( r, t ) concentration of oxygen in the solution at a distance r from the centre of the electrode and time t (mol l −1 ) C O 2 sol concentration of oxygen in the bulk of the solution (mol l −1 ) C′ O 2 sol concentration of the added oxygen (mol l −1 ) C Ox ( r, t ) concentration of the oxidised form Me( m ), at the electrode (mol l −1 ) C R ( r, t ) concentration of metal in amalgam (mol l −1 ) at a distance r from the centre of the electrode and time t C R mean concentration of metal in the drop (mol l −1 ) C R 0 initial concentration of metal in the amalgam (mol l −1 ) D Ox diffusion coefficient of the oxidised form Me( m ) in solution (cm 2 s −1 ) D R diffusion coefficient of the metal in mercury (cm 2 s −1 ) D O 2 diffusion coefficient of oxygen in mercury (cm 2 s −1 ) D Pb diffusion coefficient of Pb in mercury (cm 2 s −1 ) D Pb 2+ diffusion coefficient of Pb 2+ in solution (cm 2 s −1 ) d thickness of the diffusion layer (cm) E potential (V) E 0 standard potential of the Me m + /Me(Hg) couple (V) f 0 flux of metal at the surface of the drop (mol cm −2 s −1 ) f faraday constant=96491C Me metal used for the preparation of amalgam Me( m ) metal ion with an oxidation state of + m Me(Hg) dissolved metal in the amalgam Me m + hydrated metal ion with an oxidation state of + m m oxidation state of oxidized metal n 2p/ m p oxidation state of reduced oxygen r distance from the centre of the drop (cm) r 0 radius of the drop (cm) R gas constant=8.3 J mol −1 K −1 t time (s) τ time up to the inflection point of the curve E = f ( t ) during the oxidation of the amalgam (s) γ i successive positive roots of the equation γ=tan γ, i =1,2,3,4…

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