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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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INTERACTION Of AUROVERTIN WITH SUBMITOCHONDRIAL PARTICLES, DEfICIENT IN ATPASE INHIBITOR

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BIOCHIMICA ET BIOPHYSICA ACTA 1974年第2期347卷 224-239页

作者： VANDESTADT, RJ VANDAM, K SLATER, EC UNIV AMSTERDAM BCP JANSEN INST LAB BIOCHEM PLANTAGE MUIDERGRACHT 12 AMSTERDAM NETHERLANDS

1. Binding of aurovertin to submitochondrial particles deficient in ATPase inhibitor is accompanied by an enhancement of the fluorescence by at least 100-fold. 2. This change in fluorescence proceeds in three phases. The slowest change may be due to a conformational change in f 1 , induced by the antibiotic bound during the rapid phases, giving rise to an increase in the quantum yield of the bound fluorochrome. 3. Phosphate and ATP quench the fluorescence of the particle-aurovertin complex and ADP enhances it; the rate and extent of these changes are dependent on the availability of free Mg 2+ . 4. There is at least one binding site on the submitochondrial particles, where ATP, ADP and phosphate can bind reversibly and for which these ligands compete. These interactions are dependent on the availability of free Mg 2+ and are partly sensitive to oligomycin. 5. Binding studies reveal two binding sites for aurovertin on inhibitor-free particles, one with high affinity and one with a lower affinity. Ligands such as phosphate and ATP decrease both the quantum yield and the affinity of the particles for aurovertin. They also increase the total concentration of binding sites, and affect the relative contribution of weak and strong binding sites. 6. A model is presented in which changes of the aurovertin fluorescence reflect conformational changes of the ATPase induced by its ligands.

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 OSCP oligomycin-sensitivity-conferring protein I mitochondrial ATPase inhibitor TES N -Tris(hydroxymethyl)methyl-2-aminoethanesulphonic acid

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REVERSAL Of PACTAMYCIN INHIBITION Of METHIONYL-PUROMYCIN SYNTHESIS AND 80S INITIATION COMPLEX-fORMATION BY A RIBOSOMAL JOINING fACTOR

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PROCEEDINGS Of THE NATIONAL ACADEMY Of SCIENCES Of THE UNITED STATES Of AMERICA 1974年第10期71卷 4259-4263页

作者： SUZUKI, H GOLDBERG, IH HARVARD UNIV MED SCHDEPT PHARMACOLBOSTONMA 02115

A crude mixture of polypeptide chain initiation factors (0.5 M KCl ribosomal wash) from reticulocyte ribosomes was fractionated by DEAE-cellulose column chromatography. Among several initiation factors obtained from the column, one factor eluting at 0.22-0.25 M KCl showed a remarkable ability to overcome the inhibition of Met-puromycin and 80S initiation complex formation caused by the antibiotic, pactamycin. Earlier experiments had shown that pactamycin does not prevent the binding of Met-tRNA(f) to the small ribosomal subunit but does interfere with the joining of the 60S ribosomal subunit to form the 80S initiation complex. A Lineweaver-Burk plot of initial rates of Met-puromycin formation showed that the interaction of the factor and pactamycin was of a competitive type. In the absence of the factor, [(35)S]Met-puromycin was not synthesized and [(35)S]Met-tRNA(f) bound only to the small ribosomal subunit. The amount of [(35)S]Met-tRNA(f) bound to 80S ribosomes bearing endogenous mRNA and the amount of [(35)S]Met-puromycin formed were directly related to the amount of factor added. Thus, this factor can be termed a "joining factor," and a simple assay of its activity can be devised based on its ability to overcome the pactamycin inhibition of the puromycin reaction.

关键词： initiation factors Met-tRNA f binding Lineweaver-Burk analysis reticulocytes

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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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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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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 < 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: I T (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 I T , 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 threeexponential 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 difference

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

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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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