Antibody catalysis of the oxidation of water     

Wentworth P  Jones LH  Wentworth AD  Zhu X  Larsen NA  Wilson IA  Xu X  Goddard WA  Janda KD  Eschenmoser A  Lerner RA 《Science (New York, N.Y.)》2001,293(5536):1806-1811

Recently we reported that antibodies can generate hydrogen peroxide (H2O2) from singlet molecular oxygen (1O2*). We now show that this process is catalytic, and we identify the electron source for a quasi-unlimited generation of H2O2. Antibodies produce up to 500 mole equivalents of H2O2 from 1O2*, without a reduction in rate, and we have excluded metals or Cl- as the electron source. On the basis of isotope incorporation experiments and kinetic data, we propose that antibodies use H2O as an electron source, facilitating its addition to 1O2* to form H2O3 as the first intermediate in a reaction cascade that eventually leads to H2O2. X-ray crystallographic studies with xenon point to putative conserved oxygen binding sites within the antibody fold where this chemistry could be initiated. Our findings suggest a protective function of immunoglobulins against 1O2* and raise the question of whether the need to detoxify 1O2* has played a decisive role in the evolution of the immunoglobulin fold.  相似文献   

Horticultural Characteristics Of Licorice Waste Compost     

Shlomit Medina  Arkady Krassnovsky  Anat Yogev 《Compost science & utilization》2013,21(3):163-169

Licorice (Glycyrrhiza glabra L.) is a leguminous herbaceous perennial. Its root extracts are commonly used for medicinal uses and as a flavoring agent in the food and tobacco industries. After extraction, about 10,000 tones of licorice root residues are accumulated in Israel annually with no recycling outlet. The objectives of the current research were to develop a reliable protocol for licorice root wastes composting, to test the use of licorice compost as a peat substitute in growing media and to study its suppressiveness against Fusarium oxysporum f. sp. melonis (FOM) – the causal agent of Fusarium wilt of melon (Cucumis melo L.). Licorice root wastes were cocomposted using temperature controlled forced aeration with the coarse fraction of separated cow manure, in order to enrich both its nutrients content and microbial population. Thermophilic conditions prevailed in the pile for 90 days and the compost stabilized and reached ambient temperature 110 days from start. The physical characteristics of the resulted compost were comparable to that of peat. Nutrient content was high and salinity was relatively low. No phytotoxicity was found in the compost extract, based on the cress germination test. Tomato plants grown in compost showed enhanced development as compared to peat. The number of surviving FOM spores incubated in the compost declined faster then in peat. Fusarium infested melon plants survived much better if planted in the licorice compost, as compared to peat. It is concluded that licorice compost can serve as a peat substitute with preferable qualities.  相似文献   

Red grapefruit positively influences serum triglyceride level in patients suffering from coronary atherosclerosis: studies in vitro and in humans     

Gorinstein S  Caspi A  Libman I  Lerner HT  Huang D  Leontowicz H  Leontowicz M  Tashma Z  Katrich E  Feng S  Trakhtenberg S 《Journal of agricultural and food chemistry》2006,54(5):1887-1892

The contents of the bioactive compounds in red and blond grapefruits and their influence on humans suffering from hypertriglyceridemia were studied. It was found that red grapefruit has a higher content of bioactive compounds and a higher antioxidant potential than blond grapefruit, determined by oxygen radical scavenging capacity, 1,1-diphenyl-2-picrylhydrazyl, carotenoid bleaching, and Folin-Ciocalteu assays. Fifty-seven hyperlipidemic patients, ages 39-72 years, after coronary bypass surgery, recruited from the Institute's pool of volunteers, were randomly divided into three equal in number (19) groups: two experimental (red and blond groups) and one control group (CG). During 30 consecutive days of the investigation the diets of the patients of the red and blond dietary groups were daily supplemented with one equal in weight fresh red or blond grapefruit, respectively. Before and after this trial, serum lipid levels of all fractions and serum antioxidant activity were determined. It was found that serum lipid levels in patients of the red and blond groups versus the CG after treatment were decreased: (a) total cholesterol, 6.69 versus 7.92 mmol/L, 15.5%, and 7.32 versus 7.92 mmol/L, 7.6%, respectively; (b) low-density lipoprotein cholesterol, 5.01 versus 6.29 mmol/L, 20.3%, and 5.62 versus 6.29 mmol/L, 10.7%, respectively; (c) triglycerides, 1.69 versus 2.32 mmol/L, 17.2%, and 2.19 versus 2.32 mmol/L, 5.6%, respectively. No changes in the serum lipid levels in patients of the CG were found. In conclusion, fresh red grapefruit contains higher quantities of bioactive compounds and has significantly higher antioxidant potential than blond grapefruit. Diet supplemented with fresh red grapefruit positively influences serum lipid levels of all fractions, especially serum triglycerides and also serum antioxidant activity. The addition of fresh red grapefruit to generally accepted diets could be beneficial for hyperlipidemic, especially hypertriglyceridemic, patients suffering from coronary atherosclerosis.  相似文献   

Fresh israeli jaffa sweetie juice consumption improves lipid metabolism and increases antioxidant capacity in hypercholesterolemic patients suffering from coronary artery disease: studies in vitro and in humans and positive changes in albumin and fibrinogen fractions     

Gorinstein S  Caspi A  Libman I  Katrich E  Lerner HT  Trakhtenberg S 《Journal of agricultural and food chemistry》2004,52(16):5215-5222

The contents of the bioactive compounds in the pummelo-grapefruit hybrid juice named Israeli Jaffa Sweetie and their influence on humans suffering from hypercholesterolemia were studied. It was found that Sweetie juice has a high content of bioactive compounds and a high antioxidant potential. Then 72 hypercholesterolemic patients, ages 43-71 years, after coronary bypass surgery recruited from the Institute pool of volunteers, were randomly divided into two experimental (EG1 and EG2) groups and one control (CG) group, each comprising 24 patients. The diets of EG1 and EG2 patients were daily supplemented with 100 or 200 mL of fresh Sweetie juice, respectively. Before and after diet consumption serum lipid levels, albumin and fibrinogen fractions, and their antioxidant capacities were determined. After 30 consecutive days of Sweetie juice supplemented diets, improvements in serum lipids levels were found in EG1 and EG2 versus CG: (a) total cholesterol, 7.34 versus 8.02 mmol/L, -9.5%, and 6.73 versus 8.02 mmol/L, -16.1%, respectively; (b) low-density lipoprotein cholesterol, 5.63 versus 6.37 mmol/L, -11.6%, and 5.03 versus 6.37 mmol/L, -21.0%, respectively; (c) total glycerides, 2.01 versus 2.27 mmol/L, -11.5%, and 1.71 versus 2.27 mmol/L, -24.7%, respectively. Serum albumin concentration was increased but not significantly in EG1 and EG2 versus CG: 47.5 versus 44.5 g/L, +6.7%, and 47.9 versus 44.5 g/L, +7.6%, respectively. A significant increase in the serum, albumin, and fibrinogen antioxidant capacities in EG2 and to a lesser degree in EG1 was observed. No changes in the CG were found. In conclusion, fresh Sweetie juice contains high quantities of bioactive compounds and has a high antioxidant potential. Diet supplemented with this juice positively influences serum lipid, albumin, and fibrinogen levels and their antioxidant capacities. Addition of fresh Sweetie juice to generally accepted diets may be beneficial for hypercholesterolemic patients.  相似文献   

Soil surface water repellency induced by treated wastewater irrigation: physico-chemical characterization and quantification   总被引：2，自引：1，他引：1  

Itamar Nadav  Jorge Tarchitzky  Anat Lowengart-Aycicegi  Yona Chen 《Irrigation Science》2013,31(1):49-58

Irrigation with treated wastewater (TWW) is commonly practiced in Israel to relieve freshwater (FW) shortages. We hypothesized that the organic matter (OM) originating from TWW irrigation alters the physico-chemical properties of the soil, induces water repellency in the soil’s top layer, and consequently alters water distribution in the soil profile. In measurements taken in an avocado orchard on a clayey soil, water repellency was found in TWW-irrigated plots. In addition, smaller wetted surface areas were recorded around the drippers in comparison with FW drippers. Drier zone below soil surface was observed in TWW-emitting drippers. OM extraction from the different plots exhibited differences in quantity and quality of organic substances between TWW- and FW-irrigated soils, with a higher quantity of hydrophobic substances in the TWW-irrigated soil extract.  相似文献   

How and when was wild wheat domesticated?     

Hartmann A  Kislev ME  Weiss E 《Science (New York, N.Y.)》2006,313(5785):296; author reply 296-296; author reply 297

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Can denaturing gradient gel electrophoresis (DGGE) analysis of amplified 16s rDNA of soil bacterial populations be used in forensic investigations?     

Anat Lerner  Asya Vinokurov  Edouard Jurkevitch 《Soil biology & biochemistry》2006,38(6):1188-1192

In criminal investigations, information on the origin of soils may be crucial for solving cases. The biological complexity of soil may potentially be used for sorting and differentiating between soil samples. Nucleic-acid based analyses of soil microbial populations are powerful tools, routinely used in studies of this habitat. Application of such approaches in forensics implies that a standardized DNA extraction method has to be applied to all samples. In this study, several DNA extraction protocols were compared. An improvement on the method proposed by Tsai and Olson (1991) was found to be most suited to extract DNA from various soil types, including from small samples. A blind test on soils from a crime, an alibi scene and unrelated locations was conducted to evaluate the potential of environmental PCR and denaturating gradient gel electrophoresis for use in forensic science. In most cases, soil patterns clustered according to soil type and location.  相似文献   

Photodegradation of cassava and corn starches     

Bertolini AC  Mestres C  Raffi J  Buléon A  Lerner D  Colonna P 《Journal of agricultural and food chemistry》2001,49(2):675-682

The baking expansion properties of sour cassava starch (Polvilho azedo) are attributable to photochemical starch degradation induced by heterolactic fermentation after sun-drying. This study investigated the effects of UV irradiation on the different structural levels of cassava starch as compared to those of corn starch and dextrins. Photosensitive compounds excited at 360 and 290 nm in cassava starch were photodegraded when starch was exposed to sunlight or 360 nm irradiation. UV irradiation depolymerized cassava and corn starches, inducing modifications due, at least in part, to a mechanism involving free radicals. Lactic acid was also photodegraded. Photodegradation induced by UV absorption could have been due to fluorescent chromophores found in starches and nonfluorescent chromophores present in glucosidic units.  相似文献   

Blue-fluorescent antibodies     

Simeonov A  Matsushita M  Juban EA  Thompson EH  Hoffman TZ  Beuscher AE  Taylor MJ  Wirsching P  Rettig W  McCusker JK  Stevens RC  Millar DP  Schultz PG  Lerner RA  Janda KD 《Science (New York, N.Y.)》2000,290(5490):307-313

The forte of catalytic antibodies has resided in the control of the ground-state reaction coordinate. A principle and method are now described in which antibodies can direct the outcome of photophysical and photochemical events that take place on excited-state potential energy surfaces. The key component is a chemically reactive optical sensor that provides a direct report of the dynamic interplay between protein and ligand at the active site. To illustrate the concept, we used a trans-stilbene hapten to elicit a panel of monoclonal antibodies that displayed a range of fluorescent spectral behavior when bound to a trans-stilbene substrate. Several antibodies yielded a blue fluorescence indicative of an excited-state complex or "exciplex" between trans-stilbene and the antibody. The antibodies controlled the isomerization coordinate of trans-stilbene and dynamically coupled this manifold with an active-site residue. A step was taken toward the use of antibody-based photochemical sensors for diagnostic and clinical applications.  相似文献   

Autoimmune chorioretinitis in rhesus monkeys     

E M Lerner  S H Stone  R E Myers  L Von Sallmann 《Science (New York, N.Y.)》1968,162(853):561-562

Monkeys injected with monkey retinal tissue incorporated in Freunld's complete adjuvant developed ocular lesions characterized by choroiditic patches in the fundus periphery and sheathing of retinal vessels. Bovine retina, monkey choroid plexus, and guinea pig kidney were ineffective in this respect.  相似文献