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1.
A general method for the solid phase preparation offluorogenic peptide substrates or intramolecularly quenchedones (IQFS) is presented, using the highly fluorescentbifunctional coumarin derivative 7-amino-4-coumarinyl-acetic acid. The key feature of this method is theconjugation of H–Aca–OH through its carboxyl group on theresin, followed by the development of the peptide chainthrough its amino group, using standard Fmoc-derived solidphase peptide synthesis methodology. The 2,4-dinitrophenylgroup was used as quencher and introduced directly to theresin-bound peptides. The IQFSDnp–Lys–Pro–Ile–Cys–Phe–Ile–Lys–Leu–Aca–OH (2) andfour Dnp–X-Lys–Pro–Ile–Cys–Phe–Ile–Lys–Leu–Aca–OH (3–6), where X = Val, Lys, Ser and Glu at P6 position,potential substrates for cathepsin D, were synthesized forproving the utility of the method. The compoundsH–Ile–Lys–Leu–Aca–OH (7),H–Lys–Pro–Ile–Cys–Phe–Ile–Lys–Leu–Aca–OH (8),H–Leu–Aca–OH (9), Dnp–Leu–Aca–OH (10) and Dnp-Leu-OH (11) were also synthesized for comparisonpurposes. The fluorescence properties of compounds 9and 10 were measured. 相似文献
2.
A vector method is proposed to initially select the complexes of regulatory peptides (RPs) with certain functional characteristics. As the result of a theoretical search for the optimal combinations of anxiolytic RPs with different spectra of side effects, the following complexes are proposed for subsequent experimental investigation: NPY–ANP, NPY–SP, NPY–NT, NPY–CGRP, NPY–DSIP, NPY–MIF-1, NPY–SP–MIF-1, NPY–ANP–DSIP, and NPY–CGRP–DSIP. 相似文献
3.
Ingo Marenholz Armin Volz Andreas Ziegler Angela Davies Ioannis Ragoussis Bernhard P. Korge Dietmar Mischke 《Genomics》1996,37(3):295
The epidermal differentiation complex (EDC) unites a remarkable number of structurally, functionally, and evolutionarily related genes that play an important role in terminal differentiation of the human epidermis. It is localized within 2.05 Mb of region q21 on human chromosome 1. We have identified and characterized 24 yeast artificial chromosome (YAC) clones by mapping individual EDC genes, sequence-tagged site (STS) markers (D1S305, D1S442, D1S498, D1S1664), and 10 new region-specific probes (D1S3619–D1S3628). Here we present a contig that covers about 6 Mb of 1q21 including the entire EDC. Fluorescencein situhybridization on metaphase chromosomes with two YACs flanking the EDC determined its chromosomal orientation and established, in conjunction with physical mapping results, the following order of genes and STSs: 1cen–D1S442–D1S498–S100A10–THH–FLG–D1S1664–IVL–SPRR3–SPRR1–SPRR2–LOR–S100A9–S100A8–S100A7–S100A6–S100A5–S100A4–S100A3–S100A2–S100A1–D1S305–1qtel. These integrated physical, cytogenetic, and genetic mapping data will be useful for linkage analyses of diseases associated with region 1q21 and for the identification of novel genes and regulatory elements in the EDC. 相似文献
4.
dTDP–6–deoxy–4–keto–D–glucose (1), the common intermediate in the biosyntheses of the mainfold deoxysugars, was synthesized on a gram–scale by the combination of sucrose synthase and dTDP–D–glucose 4,6–dehydratase in a fed batch, starting the reaction with dTDP. This process allowed a dTDP conversion with a 100% rate. An easy and efficient three–step purification with anion–exchange chromatography and gel filtration gave 1.1 g of 1 in an overall yield of 73%. This work realizes a first step for an economic access to activated deoxysugars. 相似文献
5.
Nand Kumar Fageria 《Plant and Soil》1976,45(2):421-431
Summary Rice and peanut plants were grown in nutrient solution with varying concentrations of phosphorus, potassium, calcium, and magnesium. Growth response and concentration of the elements in the plant tops were recorded and from these critical and adequate values for P, K, Ca, and Mg were defined. These were for P at 25 days of growth of rice plants 0.70–0.80 and 0.80–0.86; at 50 days of growth 0.18–0.26 and 0.26–0.40; and at 75 days 0.26–0.36 and 0.36–0.48 per cent of dry matter respectively. For K they were 3.75–4.25 and 4.25–4.35 per cent at 25 days of growth; 3.7–4.0 and 4.0–4.62 per cent at 50 days of growth; and 3.5–3.62 and 3.62–3.99 per cent at 75 days of growth resp. At 100 days of growth the values for Ca and Mg were established as 0.36–0.45, 0.45–0.65; and 0.12–0.17, 0.17–0.30 per cent respectively. For 39 days old peanut plants values established for K and Mg were; 2.8–3.4, 3.4–3.8 and 0.25–0.30, 0.3–0.36 per cent resp. re]19750411 相似文献
6.
Samel M Vija H Subbi J Siigur J 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2003,135(4):575-582
We have previously shown that Vipera berus berus venom contains several factor X activating enzymes. In the present study we have investigated one of them. The enzyme was separated from venom by gel filtration on Sephadex G-100 superfine and chromatography on agarose HPS-7 and phenyl-agarose. The enzyme is a glycosylated metalloproteinase containing hexoses, hexosamines and neuraminic acid. The purified factor X activating enzyme consists of two equal chains (59 kDa). The specificity studies have shown that enzyme is nonspecific factor X activating proteinase hydrolysing also proteins such as azocasein, gelatin and fibrinogen. The enzyme hydrolyses oxidized insulin B-chain at the positions Ala14–Leu15 and Tyr16–Leu17 but it is inactive on fibrin, plasminogen and prothrombin. We used 8–10 amino acid residues containing peptides, which reproduce the sequence around the cleavage sites in factor X, factor IX and fibrinogen, as potential substrates for enzyme. Cleavage products of peptide hydrolysis were determined by MALDI-TOF MS. The peptide Asn–Asn–Leu–Thr–Arg–Ile–Val–Gly–Gly—factor X fragment was cleaved by enzyme at positions Leu3–Thr4 and Arg5–Ile6. The fibrinogen peptide fragment Glu–Tyr–His–Thr–Glu–Lys–Leu–Val–Thr–Ser was hydrolysed at position Lys6–Leu7. 相似文献
7.
M. Zouhair Atassi Behzod Z. Dolimbek Makoto Hayakari John L. Middlebrook Bruce Whitney Minako Oshima 《Journal of Protein Chemistry》1996,15(7):691-700
Botulism due to food poisoning is caused mainly by protein toxins, botulinum neurotoxins (BoNTs), produced byClostridium botluinum in seven known immunological serotypes. These are the most potent toxins and poisons known. BoNT effects blockade of neuromuscular transmission by preventing neurotransmitter release. Human botulism is most frequently caused by types A, B, and E. Recent studies have shown that immunization with a 43-kDa C-terminal fragment (HC, residues 860–1296) of BoNT/A affords excellent protection against BoNT/A poisoning. We raised antibodies (Abs) against BoNT/A in horse, and against pentavalent toxoid (BoNTs A, B, C, D, E) in human volunteers and outbred mice. Thirty-one 19-residue peptides that started at residue 855, overlapped consecutively by 5 residues, and encompassed the entire length of the HC of BoNT/A were synthesized and used for mapping the Ab-binding regions recognized by the anti-BoNT/A antisera. Horse Abs against BoBT/A were bound by peptides 855–873, 939–957, 1079–1097/1093–1111 overlap, 1191–1209/1205–1223 overlap, 1261–1279 and 1275–1296. In addition, peptides 883–901, 911–929, 995–1013, 1023–1041/1037–1055 overlap, 1121–1139, and 1149–1167 gave low, but significant and reproducible, binding. With human antisera, high amounts of Abs were bound by peptides 869–887, 925–943, 981–999, 995–1013, 1051–1069, and 1177–1195. In addition, lower amounts of Abs were bound by peptides 911–929, 939–957, 967–985, and the overlaps 1121–1139/1135–1153 and 1247–1265/1261–1279/1275–1296. With outbred mouse antisera, high amounts of Abs were bound by peptides 869–887, 1051–1069, and 1177–1195, while peptides 939–957, 995–1013, 1093–1111, and 1275–1296 bound lower amounts of Abs. The results indicate that horse antiserum against BoNT/A or human and mouse (outbred) antisera against the toxoid recognized similar regions on BoNT/A, but exhibited some boundary frame shifts and differences in immunodominance of these regions among the antisera. Selected synthetic epitopes will be used as immunogens to stimulate active or passive (by Ab transfer) immunity against toxin poisoning.Abbreviations Ab
antibody
- BoNT
botulinum neurotoxin
- BoNT/A
BoNT type A
- BSA
bovine serum albumin
- CFA
complete Freund's adjuvant
- HC
C-terminal fragment corresponding to residues 860-1296 of the heavy chain of BoNT/A
- PBS
0.15 M NaCl in 0.01 M sodium phosphate buffer,
p
H 7.2
- TeTX
tetanus toxin 相似文献
8.
Christian Mueller-Eckhardt Dieter Heinrich Karin Mersch-Baumert Andreas Czitrom Peter Walker 《Human genetics》1974,24(4):319-324
Summary 1047 healthy, random blood donors were typed independently for HL-A antigens by platelet complement fixation and lymphocytotoxicity. The results of both methods were analyzed statistically and the gene frequencies calculated. The gene frequencies were: first HL-A locus: 1: 0.1277–0.1316; 2: 0.3018–0.3053; 3: 0.1411–0.1456; 9: 0.1061–0.1088; 10: 0.0540–0.0564; 11: 0.0381–0.0416; W28: 0.0096–0.0271; W32: 0.0365–0.0469; second HL-A locus: 5: 0.0613–0.0649; 7: 0.1367–0.1401; 8: 0.0716–0.0920; 12: 0.0383–0.0903; 13: 0.0357–0.0371; W5: 0.0786–0.0844; W10: 0.0594–0.0620; W14: 0.0280–0.0315; W15: 0.0650–0.0722; W17: 0.0399; W18: 0.0241–0.0374; W22: 0.0037–0.0161; W27: 0.0406–0.0532; W21: 0.0329–0.0428. The discrepancies of typing results are discussed and their practical importance for paternity serology is stressed.Supported by the Deutsche Forschungsgemeinschaft (Mu 277/5). 相似文献
9.
Autoantibodies directed to a variety of cellular antigens and organelles are a feature of autoimmune diseases. They have proven useful in a clinical setting to establish diagnosis, estimate prognosis, follow disease progression, alter therapy, and initiate new investigations. Cellular and molecular biologists have used autoantibodies as probes to identify molecules involved in key cellular processes. One of the most interesting sets of autoantibodies are those that target antigens within the mitotic apparatus (MA). The MA includes chromosomes, spindle microtubules and centrosomes. The identification, localization, function, and clinical relevance of MA autoantigens is the focus of this review. Abbreviations: ATP – adenosine triphosphate; CENP – centromere protein; CREST – calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia; HMG – high mobility group; IB – intercellular bridge; IIF – indirect immunofluorescence; MAPs – microtubule associated proteins; NuMA – nuclear mitotic apparatus; NOR – nucleolar organizer; PBC – primary biliary cirrhosis; PM – polymyositis; Pol I, II, III – RNA polymerases; RA-rheumatoid arthritis; SLE – systemic lupus erythematosus; SS – Sjögren's syndrome; SSc – systemic sclerosis; topo – topoisomerase. 相似文献
10.
Abbreviations: 434(1–63) – N-terminal 63-residue DNA-binding domain of the phage 434 repressor; dh434(0–63) – variant 434 repressor DNA-binding domain devoid of hydroxyl groups; P22c2(1–76) – N-terminal 76-residue fragment of the phage P22 c2 repressor; SDS-PAGE – SDS polyacrylamide gel electrophoresis; COSY – correlation spectroscopy; TOCSY – total correlation spectroscopy; NOE – nuclear Overhauser effect; RMSD – root-mean-square deviation. 相似文献
11.
Data on linkage of 12 rye genes controlling morphological traits (el, Vs, ln, w, np, ct2, Hs, Ddw, cb, mn, vi1, mp) with one or several isozyme markers of individual rye chromosomes (2R–7R) are presented. Linkage of the following gene pairs was established: chromosome 2R: Est3/5–el, el–-Glu, Sod2–el, Sod2–Vs; chromosome 3R: ln–Got4; chromosome 4R: w–Got1, np–Got1; chromosome 5R: Est4–ct2, Est6/9–ct2, ct2–Est2, ct2–Aco2, Est2–Hs, Aco2–Hs, Est2–Ddw, Aco2–Ddw; chromosome 6R:Lap2–cb, cb–Aco1, Est10–mn; chromosome 7R: Acph2/3–vi1, Got2–vi1, mp–Acph2/3. The reasons for mapping a very small number of genes in rye in spite of high intraspecific variability of this species are discussed. An approach is suggested to improve this situation by simultaneous identification and mapping of all diverse spontaneous mutations maintained in heterozygous state in various rye cultivars. 相似文献
12.
Dry matter and nutrient inputs through litter fall in a dry tropical forest of India 总被引:1,自引:0,他引:1
Lalji Singh 《Plant Ecology》1992,98(2):129-140
The present paper elucidates the pattern of leaf and non-leaf fall and quantifies of the total annual input of litter in a dry tropical forest of India. In addition, concentration of selected nutrients in various litter species and their annual return to the forest floor are examined. Total annual input of litter measured in litter traps ranged between 488.0–671.0 g m-2 of which 65–72% was leaf litter fall and 28–35% wood litter fall. 73–81% leaves fall during the winter season. Herbaceous litter fall ranged between 80.0–110.0 g m-2 yr-1. The annual nutrient return through litter fall amounted (kg ha-1): 51.6–69.6 N, 3.1–4.3 P, 31.0–40.0 Ca, 14.0–19.0 K and 3.7–5.0 Na, of which 71–77% and 23–29% were contributed by leaf and wood litter fall, respectively for different nutrients. Input of nutrients through herbaceous litter was: 13.0–16.6 for N, 1.0–1.4 for P, 4.0–5.0 for Ca, 7.9–10.5 for K and 0.8–1.0 kg ha-1 yr-1 for Na. 相似文献
13.
Ground-based measurements of stores, growth, mortality, litterfall, respiration, and decomposition were conducted in an old-growth forest at Wind River Experimental Forest, Washington, USA. These measurements were used to estimate gross primary production (GPP) and net primary production (NPP); autotrophic respiration (Ra) and heterotrophic (Rh) respiration; and net ecosystem production (NEP). Monte Carlo methods were used to calculate uncertainty (expressed as ± 2 standard deviations of 200–400 calculations). Live carbon (C) stores were 39,800 g C m–2 (34,800–44,800 g C m–2). The store of C in detritus and mineral soil was 22,092 g C m–2 (20,600–23,600 g C m–2), and the total C stores were 61,899 g C m–2 (56,600–67,700 g C m–2). Total NPP was 597 g C m–2 y–1 (453 to 741 g C m–2 y–1). Ra was 1309 g C m–2 y–1 (845–1773 g C m–2 y–1), indicating a GPP of 1906 g C m–2 y–1 (1444–2368 g C m–2 y–1). Rh, including the respiration of heart rots in tree boles, was 577 g C m–2 y–1 (479–675 g C m–2 y–1). Long-term NEP was estimated to be +20 g C m–2 y–1 (–116 to +156 g C m–2 y–1), indicating this stand might be a small sink. These estimates contrast with the larger sink estimated at the same site using eddy-flux methods. Several hypotheses to explain this discrepancy were explored, including (a) undetected biomass increases, (b) underestimates of NPP, (c) unmeasured losses, and (d) a temporal mismatch between the two sets of measurements. The last hypothesis appears the most likely. 相似文献
14.
Experimental carbonate blocks of coral skeleton,Porites lobata (PL), and cathedral limestone (LS) were deployed for 14.8 months at shallow (5–6 m) and deep (11–13m) depths on a severely bioeroded coral reef, Champion Island, Galápagos Islands, Ecuador. Sea urchins (Eucidaris thouarsii) were significantly more abundant at shallow versus deep sites.Porites lobata blocks lost an average of 25.4 kg m–2yr–1 (23.71 m–2yr–1 or 60.5% decrease yr–1). Losses did not vary significantly at depths tested. Internal bioeroders excavated an average of 2.6 kg m–2 yr–1 (2.41 m–2 yr–1 or 0.6% decrease yr–1), while external bioeroders removed an average of 22.8 kg m–2 yr–1). (21.31 m–2 yr–1). or 59.9% decrease yr–1). few encrusting organisms were observed on the PL blocks. Cathedral limestone blocks lost an average of 4.1 kg m–2 yr–1). (1.81 m–2 yr–1). or 4.6% decrease yr-'), also with no relation to depth. Internal bioeroders excavated an average of 0.6 kg m–2 yr–1). (0.31 m–2 yr–1). or 0.7% decrease yr–1). and external bioeroders removed an average of 3.5 kg m–2 yr–1). (1.51 m–2 yr–1). or 3.9% decrease yr–1). from the LS blocks. Most (57.6%) encrustation occurred on the bottom of LS blocks, and there was more accretion on block bottoms in deep (61.4 mg cm–2 yr–1). versus shallow (35.0 mg cm–2 yr–1) sites. External bioerosion reduced the average height of the reef framework by 0.2 cm yr–1). for hard substrata (represented by LS) and 2.3 cm yr–1). for soft substrata (represented by PL). The results of this study suggest that coral reef frameworks in the Galápagos Islands are in serious jeopardy. If rates of coral recruitment do not increase, and if rates of bioerosion do not decline, coral reefs in the Galápagos Islands could be eliminated entirely. 相似文献
15.
The shallow, brackish (11–18% salinity) Roskilde Fjord represents a eutrophication gradient with annual averages of chlorophyll, ranging from 3 to 25 mg chl a m–3. Nutrient loadings in 1985 were 11.3–62.4 g N m–2 yr–1 and 0.4–7.3 g P m–2 yr–1. A simple one-layer advection-diffusion model was used to calculate mass balances for 7 boxes in the fjord. Net loss rates varied from –32.2 to 17.9 g P m–2 yr–1 and from –3.3 to 66.8 g N m–2, corresponding to 74% of the external P-loading and 88% of the external N-loading to the entire estuary.Gross sedimentation rates measured by sediment traps were between 7 and 52 g p m–2 yr–1 and 50 and 426 g N M–2 yr–1, respectively. Exchangeable sediment phosphorus varied in annual average between 2.0 and 4.8 g P m–2 and exchangeable sediment nitrogen varied from 1.9 to 33.1 g N m–1. Amplitudes in the exchangeable pools followed sedimentation peaks with delays corresponding to settling rates of 0.3 m d–1. Short term nutrient exchange experiments performed in the laboratory with simultaneous measurements of sediment oxygen uptake showed a release pattern following the oxygen uptake, the changes in the exchangeable pools and the sedimentation peaks.The close benthic-pelagic coupling also exists for the denitrification with maxima during spring of 5 to 20 mmol N m–2 d–1. Denitrification during the nitrogen-limited summer period suggests dependence on nitrification. Comparisons with denitrification from other shallow estuaries indicate a maximum for denitrification in estuaries of about 250 µmol N m–2 h–2 achieved at loading rates of about 25–125 g N m–2 yr–1. 相似文献
16.
Yamile Gonzlez Aparecida S. Tanaka Izaura Y. Hirata Maday Alonso del Rivero Maria L.V. Oliva Mariana S. Araujo Maria A. Chvez 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,146(4):506
Human neutrophil elastase inhibition was detected in a crude extract of the marine snail Cenchritis muricatus (Gastropoda, Mollusca). This inhibitory activity remained after heating this extract at 60 °C for 30 min. From this extract, three human neutrophil elastase inhibitors (designated CmPI–I, CmPI–II and CmPI–III) were purified by affinity and reversed-phase chromatographies. Homogeneity of CmPI–I and CmPI–II was confirmed, while CmPI–III showed a single peak in reversed-phase chromatography, but heterogeneity in SDS-PAGE with preliminary molecular masses in the range of 18.4 to 22.0 kDa. In contrast, MALDI-TOF mass spectrometry of CmPI–I and CmPI–II showed that these inhibitors are molecules of low molecular mass, 5576 and 5469 Da, respectively. N-terminal amino acid sequences of CmPI–I (6 amino acids) and CmPI–II (20 amino acids) were determined. Homology to Kazal-type protease inhibitors was preliminarily detected for CmPI–II. Both inhibitors, CmPI–I and CmPI–II are able to inhibit human neutrophil elastase strongly, with equilibrium dissociation constant (Ki) values of 54.2 and 1.6 nM, respectively. In addition, trypsin and pancreatic elastase were also inhibited, but not plasma kallikrein or thrombin. CmPI–I and CmPI–II are the first human neutrophil elastase inhibitors described in a mollusk. 相似文献
17.
Abbreviations EGTA – ethylene bis(oxyethylenenitrilo)-tetraacetic acid; F12 – Ham's F12; FBS – foetal bovine serum; HBSS – Hank's balanced salt solution; HDM – hormonally defined medium; HEPES – 4-(2-hydroxyethyl)-1-piperazine ethanesulphonic acid; NBS – new born calf serum; WME – Williams' medium E. 相似文献
18.
Macroposthonia napoensis n. sp. and M. planilobata n. sp. from Ecuador are described and illustrated. Differential characters of M. napoensis are: first annule with four enlarged submedian lobes but not giving the lip region a disc–like appearance , vagina sigmoid, none or very few anastomoses, a poorly–developed spermatheca, L = 0.33–0.42 mm, V = 89–93, stylet = 55–74 µ and R = 73–79. M. planilobata n. sp. can be distinguished by the four large and anteriorly flattened submedian lobes which give the lip region a disc–like appearance, a sigmoid vagina, a conoid–rounded tail with coarse annules, L = 0.41–0.49 mm, a = 11.3–13.3, V = 90–94, stylet = 66.5–78.5 µ and R = 75–84. Measurements from populations of Discocriconemella limitanea and M. surinamensis from Ecuador are also provided. D. repleta is accepted as a junior synonym of D. limitanea, and D. heynsi Van den Berg & Marais, 1995 is proposed as a junior synonym of M. surinamensis. 相似文献
19.
Unionid clams were collected at 1–2 m, 3–4 m and 6–7 m depth in lake Mattsee, a moderately mesotrophic lake, to investigate the effect of depth on clam growth and age structure. No significant differences in age structure of Anodonta cygnea were found (p=0.65). Three and ten years old clams were present at all depths, but in different percentages. Whereas at 1–2 m 13.3% of the collected clams were <4 years old, this percentage was 4.4% at 6–7 m and 7.1% at 3–4 m. A greater percentage (6.7%) of older mussels (9, 10 years) were collected at 6–7 m than at 1–2 m (2.2%). Growth declined with depth. Total length at a given age of clams at 1–2 m and 3–4 m did not differ (p=0.54), whereas differences were significant between clams at 1–2 m and 6–7 m (p<0.05) as well as between 3–4 m and 6–7 m (p<0.05). The Growth constant k was highest at 1–2 m depth. 相似文献
20.
Todd Ellingson Sushil Duddempudi Benjamin D. Greenberg Douglas Hooper Graeme Eisenhofer 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1999,729(1-2)
Catechol-O-methyltransferase (COMT) exists as two isoenzymes, a membrane-bound form (MB–COMT) and a soluble form (S–COMT), with different roles in the metabolism of catecholamines and other catechol compounds. This report documents an HPLC assay for separate estimation of S–COMT and MB–COMT activity and examines activities of the two isoezymes among different rat tissues and in human and rat erythrocytes. Activities of MB–COMT and S–COMT varied widely among tissues. There were higher activities of S–COMT than MB–COMT in all tissues except the adrenal medulla where MB–COMT was the predominant isoenzyme, consistent with the importance of this tissue and MB–COMT for the O-methylation of catecholamines. MB–COMT and S–COMT in rat and human erythrocytes showed divergent levels and patterns of activity. The assay represents a rapid and accurate method for quantifying MB–COMT and S–COMT in various tissues and examining the relative roles of COMT isoenzymes in the metabolism of catechol compounds in health and disease. 相似文献