Moshe Weisz

Intrinsic Tryptophan Fluorescence of Human Serum Proteins and Related Conformational Changes

The unfolding of human serum proteins (HSP) was studied by measuring the intrinsic fluorescence intensity at a wavelength of excitation corresponding to tryptophans or typosines fluorescence and surface hydrophobicity. The maxima emission wavelengths (λmax) of human serum albumin (HSA) and human serum globulin (HSG) before beer consumption (BC) were 336.0 and 337.0 nm and after BC shifted to 335.0 and 334.0 nm, respectively. The surface hydrophobicity slightly increased after BC. In a solution of 8 M urea the λmax of BSA shifted to 346.4 and that of BSG to 342.5 nm. In contrast, in the same solution but after BC the λmax positions of HSA and HSG shifted to 355.9 and 357.7 nm, respectively. A decrease in fluorescence intensity, a shift in the maximum of emission, and an increase in surface hydrophobicity which reflected unfolding of proteins were observed. Here we provide evidence that the loosening of the HSP structure takes place primarily in various concentrations of urea before and after beer consumption. Differences in the fluorescence behavior of the proteins are attributed to disruption of the structure of proteins by denaturants as well as by the change in their compactability as a result of ethanol consumption.

The influence of alcohol-containing and alcohol-free beverages on lipid levels and lipid peroxides in serum of rats

It is an established fact that moderate consumption of alcoholic beverages leads to some positive biochemical changes in blood that are widely regarded as indicators of improved prevention of atherosclerosis. However, at present, there are different opinions regarding the biologically active compounds of alcoholic beverages that bring about these changes. This experiment was conducted on 60 male Wistar rats, which were divided into five groups, each of which contained 12 rats: four experimental groups (EG1, EG2, EG3, EG4) and one control group (CG). During 4 weeks, all groups of rats were fed basal diet (BD) supplemented with dry red wine (EG1), beer (EG2), lyophilized dry red wine (EG3), or lyophilized beer (EG4). The rats of the CG were fed BD only. The rats of EG1 and EG2 were fed BD supplemented daily with 2.0 mL of wine and 6.0 mL of beer, respectively. The rats of EG3 and EG4 were fed BD supplemented daily with lyophilized wine and lyophilized beer at a concentration corresponding to an intake of 2.0 mL of original wine and 6.0 mL of original beer, respectively. Before and after completion of the trial, a wide range of laboratory tests including lipids and lipid peroxides were performed. The results of this investigation reveal that both original and lyophilized wine and beer exercise statistically significant beneficial lipidemic and antioxidant effects by reducing total cholesterol (TC), low density lipoprotein cholesterol, triglycerides, and lipid peroxides ( , 0.05 for all) and by elevating the high density lipoprotein cholesterol:TC ratio. There were no statistically significant differences in the results between groups fed BD supplemented with original wine and beer versus groups fed BD supplemented with lyophilized wine and beer. Therefore, it can be concluded that the biologically active compound of these beverages is their dry matter containing inter alia polyphenols in relatively high concentrations. (J. Nutr. Biochem. 9:682‐ 686, 1998)

Spectroscopic Analysis of Polyphenols in White Wines

Abstract Spectroscopic analysis was used to study the effect of wine processing on phenolic composition. Various classes of phenolic compounds were detected and characterized by ultraviolet (UV) and infrared (IR) spectroscopy in white grapes of Sauvignon Blanc and French Colombard, as well as in wines prepared from these grapes. Combined treatment with bentonite, egg albumin and Polyclar AT decreased the amounts of catechols, flavonols, anthocyanins and leucoanthocyanins. Polyphenols (32–17%), anthocyanogens (64–48%) and proteins (62–77%) were removed by this technological process. The best results were received when not only wines, but also musts were pretreated with bentonite. Comparisons of the polyphenol compositions of wines made from the same grape variety grown in different locations of the same vintage and between two vintages are reported.

The influence of dry matter of different alcoholic beverages on lipids, proteins, and antioxidant activity in serum of rats

Abstract In many western industrialized countries alcoholic beverages are an invariable component of different diets. In the last couple years evidence that moderate consumption of alcoholic beverages leads to some beneficial changes in lipid metabolism and in this way reduces the morbidity and mortality from coronary artery disease (CAD) has been found. In this study we examined the influence of diets supplemented with different lyophilized wines and beer on lipids, proteins, and antioxidant activity in serum of rats. The investigation was conducted on 60 male Wistar rats, divided into three experimental (EG) and one control (CG) groups, each comprised of 15 animals. The rats of the three EGs were fed basic diet (BD) supplemented with South African (SA) dry red wine (EG1), SA dry white wine (EG2), and Israeli Maccabee beer (EG3). The rats of the CG were fed BD only. During 4 weeks of our experiment the animals of EG3 were fed BD supplemented with lyophilized beer at a concentration corresponding to an intake of 6.0 mL of original beer and the rats of EG1 and EG2 were fed BD supplemented with lyophilized wine at a concentration 2.0 mL of original wine daily. Before and after completion of the trial we performed a wide range of laboratory tests including lipids, proteins, and lipid peroxides. The results of our investigation reveal that the dry matter of red wine and beer are the most effective beverages: they exercise beneficial lipidemic and antioxidant effects by reducing total cholesterol (TC), triglycerides, and lipid peroxides and elevating high-density lipoprotein (HDL-C)/TC ratio. All used beverages do not effect the level of proteins in serum of the rats.

Comprehensive two-dimensional gas chromatography and three-dimensional fluorometry for detection of volatile and bioactive substances in some berries

The volatile fractions of Cape gooseberry and blueberry were determined by headspace solid-phase microextraction coupled with comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (HS-SPME/GC×GC-TOFMS). The highest amount of alcohol (51.8%), ester (32.8%) and carboxylic acid (6.9%) was in blueberry in comparison with gooseberry and oppositely ketones (14.7%), aldehydes (9.9%) and terpenes (8%) were found in gooseberry. The bioactive compounds and antioxidant capacities were higher in blueberries than in gooseberries. Three dimensional fluorescence emission spectrometry (3D-FL) was applied to determine and to compare experimentally found binding parameters of berries extracts with human serum albumin (HSA). The fluorescence quenching of HSA by polyphenols from berries was a result of the formation of a polyphenol-HSA complex. The binding abilities of berries were highly correlated with the bioactivity of polyphenols and volatile substances. The cluster analysis (CA) and linear discriminant analysis (LDA) was applied to differentiate the berries samples according to their type.

Proteins of beer affect lipid levels in rats

Consumption of dry matter of alcoholic beverages leads to improved lipid metabolism and increased antioxidant activity in experiments on rats. Proteins and amino acids are part of the dry matter. Are proteins and amino acids playing a role in these changes? Amino acid analysis, electrophoretic separation and Fourier transform-infrared spectra (FT-IR) were used to determine and characterize proteins and amino acids in beer and white wine. The contents of total proteins, albumin and of most studied amino acids in beer were significantly higher than in white wine (P , 0.05‐ 0.0005). Thirty-six rats were divided in 3 groups, each 12. The rats of the Control group were fed basal diet (BD) only and the BD of the two experimental groups (B and WW) was supplemented with lyophilized, polyphenol-free beer and white wine, respectively. Before and after completion of the 4 weeks feeding period, total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol, triglycerides (TG) and lipid peroxides (LP) were examined. Only in the group of rats (B) fed diet, supplemented with beer a significant decrease in the level of TC, LDL-C and TG was observed (P, 0.05, 0.05 and 0.005, respectively). No differences in the level of LP in all 3 groups were found. Therefore, only diet supplemented with lyophilized, polyphenol-free beer, which has significantly higher concentration of proteins and essential amino acids than white wine does affect the level of

Analytical Methods Applied to Characterization of Actinidia arguta, Actinidia deliciosa, and Actinidia eriantha Kiwi Fruit Cultivars

AbstractIn this research, eight kiwi fruit genotypes (six hardy kiwis (Actinidia arguta and their hybrids), one of Actinidia deliciosa ‘Hayward,’ and one of Actinidia eriantha ‘Bidan’ were examined and compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared (FT-IR) spectra, and nuclear magnetic resonance (NMR) spectroscopy. Proteins were extracted from lyophilized fruits, flesh with seeds, grinded seeds, and singular seeds and then separated by SDS-PAGE. Matrix similarity and dendrogram was generated using Nei coefficient and Unweighted Pair Group Method with Arithmetic mean (UPGMA) algorithm. Based on protein patterns, Actinidia species were clearly distinguishable, whereas differences between hardy kiwi fruit cultivars were minor or nondetectable. The electrophoretical separations were able to distinguish a half of hardy kiwi fruit cultivars, so cluster analysis revealed a limited number of cultivar groups. Intervarietal polymorphism was low and this affected the results of similarity analysis. One distinct cluster, composed of two pairs of cultivars and identical by protein patterns, was obtained. Cultivars ‘Ananasnaya’ and ‘Weiki,’ according to the morphological description, were similar. Oppositely, ‘M1’ cultivar significantly differed from other hardy kiwi cultivars by densitometrical bands intensity. All examined singular seeds of ‘Ananasnaya’ cultivar possessed identical protein patterns. The protein patterns of ‘Bingo’ and ‘Ananasnaya’ hardy kiwi fruits harvested in 2011 and 2013 were identical. Three weeks storage after harvest did not affect the protein composition of these cultivars. FT-IR and NMR spectrum of hardy kiwi fruits were presented and compared with ‘Hayward’ and ‘Bidan’ and showed slight differences in comparison with the protein profiles. SDS-PAGE is more applicable than FT-IR and NMR for comparison of different kiwi fruit cultivars. The used analytical methods can be applied to any food analysis in order to distinguish the main compounds and to present fingerprints of different cultivars. Graphical AbstractA, Actinidia arguta kiwi fruit cultivars; B, Actinidia deliciosa kiwi fruit ‘Hayward’; C,Actinidia eriantha kiwi fruit ‘Bidan’; D, Electrophoretical patterns of proteins extracted with urea bufferfrom: 1, ‘Bingo’; 2, ‘M1’; 3, ‘Ananasnaya’; 4, ‘Weiki’; 5, ‘Jumbo’; 6, ‘Geneva’; 7, ‘Hayward’; 8,‘Bidan’; E, FT-IR spectra of extracted polyphenols. Curves from the top kiwi fruit ‘Ananasnaya,’‘Bingo,’ ‘M1’; F, 1H-NMR spectra from the top of DMSO extracts of ‘Bidan’; ‘Hayward’;‘Ananasnaya’.

A Simple and Stable Silica Gel Support for the Oligodeoxyribonucleotide Synthesis

Abstract A simple and efficient synthesis of a solid support with a long chain polyamide spacer has been developed. The spacer was made by successive addition of ethylene-diamine and succinic anhydride. The obtained solid support gives very homogeneous 20 mer oligodeoxyribonucleotides, detected by HPLC and electrophoresis.

An Improved Method for the Preparation of Methyl dichlorophosphite. A Key Reagent In the Phosphite Method of Oligonucleotide Synthesis

Abstract The reaction between phosphorus trichloride (PCl3) and trimethyl phosphite (CH3O)3p, has been examined by 31Pnmr, in order to achieve a simple and efficient procedure for the formation of methyl dichlorophosphite (CH3OPCl2), which is a key intermediate in the synthesis of oligonucleotides. The yield of the reaction was also studied on a preparative scale and it was found that the optimal condition is obtained when the reactants molar ratio is 1:1.

Spacer effect on the synthesis of oligodeoxynucleotides by the phosphite method

Abstract Nineteen oligonucleotides of 15–27 bases long were synthesized on aminoalkyl spacers of various chain lengths, SiO(CH2)3NHCONH(CH2)nNHCO(CH2)mNH2, linked to Fractosil silica gel supports (F6, F12, F15, F18, F21, F24, F32, F38), to Porasil (P15) silica gel support, and to modified controlled pore glass (CPG17, CPG24). The purity and the homogenity of the end product in the reaction mixture was quantitatively determined from the autoradiograph pattern of bands on polyacrylamide sizing gel. The data indicated that the most pure products are obtained either on the shortest spacer, F6, or on the 24, 32, or 38 atom length spacers. Spacer lengths of 15, 18 and 21 atoms gave very poor results, with large amounts of impurities. The results are interpreted on the basis of conformational changes in the spacer alkyl chain as a function of its length.