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101.
William M. Laird John F. March Vilas K. Newby Richard L.M. Synge 《Phytochemistry》1979,18(9):1501-1503
During aerobic autolysis and in commercial curing, the bulk proteins of tobacco leaves become coupled with quinic acid, presumably in consequence of coupling of chlorogenic acid congeners with lysine ε-NH2 groups. Quinic acid derivatives, prepared from acid hydrolysates of such altered proteins, were identified by GC-MS. Such proteins were also hydrogenated over Rh/Al2O3 with a view to stabilizing the hypothetical linkages. Difficulties in removing contaminant Al had to be overcome. Evidence was then obtained (by GLC of derivatives) for several components, in acid hydrolysates of hydrogenated altered proteins, which were neither normal hydrogenation products of the common amino acids nor derivatives of quinic acid. Details of the chromatograms and mass spectra of quinic acid derivatives are provided in a supplementary publications. 相似文献
102.
T C Newby 《Journal of mammalogy》1973,54(2):540-543
103.
Allysa Adams Brandeis McBratney-Owen Brittany Newby Margot E. Bowen Bjorn R. Olsen Matthew L. Warman 《Mammalian genome》2013,24(1-2):54-62
Cranial base growth plates are important centers of longitudinal growth in the skull and are responsible for the proper anterior placement of the face and the stimulation of normal cranial vault development. We report that the presphenoidal synchondrosis (PSS), a midline growth plate of the cranial base, closes in the DBA/2J mouse strain but not in other common inbred strains. We investigated the genetics of PSS closure in DBA/2J mice by evaluating F1, F1 backcross, and/or F1 intercross offspring from matings with C57BL/6J and DBA/1J mice, whose PSS remain open. We observed that PSS closure is genetically determined, but not inherited as a simple Mendelian trait. Employing a genome-wide SNP array, we identified a region on chromosome 11 in the C57BL/6J strain that affected the frequency of PSS closure in F1 backcross and F1 intercross offspring. The equivalent region in the DBA/1J strain did not affect PSS closure in F1 intercross offspring. We conclude that PSS closure in the DBA/2J strain is complex and modified by different loci when outcrossed with C57BL/6J and DBA/1J mice. 相似文献
104.
Sherman J. Bigornia Michael P. LaValley Li L. Benfield Andy R. Ness P.K. Newby 《Obesity (Silver Spring, Md.)》2013,21(10):2055-2062
Objective: The relationship between central and total fat measured by anthropometry, dual energy X‐ray absorptiometry, and magnetic resonance imaging (MRI) with each other and systolic blood pressure (SBP) was examined. Design and Methods: Participants of the Avon Longitudinal Study of Parents and Children were examined at ages 9, 11, 13, and 15 years (n = 3,796‐6,567). MRI was available on a subset of children at 11 (n = 156) and 13 (n = 95). Results: Body mass index (BMI) and waist circumference (WC) were highly correlated (r = 0.84‐0.91, across ages), and total body fat mass (TBFM) and trunk fat mass (TFM) were very strongly correlated (r ≥ 0.98). Among boys, BMI vs. WC explained a similar degree of variation in TBFM and TFM (41‐71% vs. 43‐76%, across age and overweight groups); in girls, BMI accounted for 62‐73% variance and WC 47‐69%. Adiposity measures were generally similarly correlated with SBP within age groups. Further, the relationship between intra‐abdominal adipose tissue (IAAT) volume and adiposity measures did not vary greatly at 11 (0.65‐0.67) and 13 (0.64‐0.67). Conclusions: BMI and WC contain a large amount of overlapping information as evidenced by their high correlation and similarly sized associations with fat mass, SBP, and IAAT. This suggests that WC may be an inadequate marker of central adiposity during childhood. 相似文献
105.
Gene expression can be altered by small molecules that target DNA; sequence as well as shape selectivities are both extremely important for DNA recognition by intercalating and groove‐binding ligands. We have characterized a carbohydrate scaffold (1) exhibiting DNA “shape readout” properties. Thermodynamic studies with 1 and model duplex DNAs demonstrate the molecule's high affinity and selectivity towards B* form (continuous AT‐rich) DNA. Isothermal titration calorimetry (ITC), circular dichroism (CD) titration, ultraviolet (UV) thermal denaturation, and Differential Scanning Calorimetry were used to characterize the binding of 1 with a B* form AT‐rich DNA duplex d[5′‐G2A6T6C2‐3′]. The binding constant was determined using ITC at various temperatures, salt concentrations, and pH. ITC titrations were fit using a two‐binding site model. The first binding event was shown to have a 1:1 binding stoichiometry and was predominantly entropy‐driven with a binding constant of approximately 108 M?1. ITC‐derived binding enthalpies were used to obtain the binding‐induced change in heat capacity (ΔCp) of ?225 ± 19 cal/mol·K. The ionic strength dependence of the binding constant indicated a significant electrolytic contribution in ligand:DNA binding, with approximately four to five ion pairs involved in binding. Ligand 1 displayed a significantly higher affinity towards AT‐tract DNA over sequences containing GC inserts, and binding experiments revealed the order of binding affinity for 1 with DNA duplexes: contiguous B* form AT‐rich DNA (d[5′‐G2A6T6C2‐3′]) >B form alternate AT‐rich DNA (d[5′‐G2(AT)6C2‐3′]) > A form GC‐rich DNA (d[5′‐A2G6C6T2‐3′]), demonstrating the preference of ligand 1 for B* form DNA. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 720–732, 2014. 相似文献
106.
Muhammad Zia-Ul-Haq Shakeel Ahmad Shazia Anwer Bukhari Ryszard Amarowicz Sezai Ercisli Hawa ZE Jaafar 《Biological research》2014,47(1)
Background
In recent years, the desire to adopt a healthy diet has drawn attention to legume seeds and food products derived from them. Mash bean is an important legume crop used in Pakistan however a systematic mapping of the chemical composition of mash bean seeds is lacking. Therefore seeds of four mash bean (Vigna mungo (L.) Hepper, family Leguminoseae) cultivars (NARC-Mash-1, NARC-Mash-2, NARC-Mash-3, NARC-Mash-97) commonly consumed in Pakistan have been analyzed for their chemical composition, antioxidant potential and biological activities like inhibition of formation of advanced glycation end products (AGE) activity and tyrosinase inhibition activity.Results
The investigated cultivars varied in terms of biochemical composition to various extents. Mineral composition indicated potassium and zinc in highest and lowest amounts respectively, in all cultivars. The amino acid profile in protein of these cultivars suggested cysteine is present in lowest quantity in all cultivars while fatty acid distribution pattern indicated unsaturated fatty acids as major fatty acids in all cultivars. All cultivars were found to be rich source of tocopherols and sterols. Fourier transform infrared spectroscopy (FTIR) fingerprints of seed flour and extracts indicated major functional groups such as polysaccharides, lipids, amides, amines and amino acids. Results indicated that all investigated cultivars possessed appreciable antioxidant potential.Conclusions
All cultivars are rich source of protein and possess sufficient content of dietary fiber, a balanced amino acid profile, low saturated fatty acids and antioxidant capacity that rationalizes many traditional uses of seeds of this crop besides its nutritional importance. The collected data will be useful for academic and corporate researchers, nutritionists and clinical dieticians as well as consumers. If proper attention is paid, it may become an important export commodity and may fetch considerable foreign exchange for Pakistan. 相似文献107.
通过细胞免疫、体液免疫、单核巨噬细胞吞噬功能、NK细胞活性测定试验检验由植物乳植杆菌HEAL9和副干酪乳酪杆菌8700:2配制而成的复合益生菌粉对小鼠免疫力功能的影响。
将50只雄性BALB/c小鼠按体质量随机分为阴性对照组、阳性对照组以及益生菌粉低、中和高剂量组,每组10只,分别使用去离子水、转移因子口服液和相应浓度的益生菌粉进行灌胃给药,1次/d,连续30 d。实验过程中分别对小鼠进行迟发型变态反应试验、抗体生成细胞检测及血清溶血素生成试验。末次给药次日,对小鼠进行淋巴细胞转化的影响试验、碳廓清试验和腹腔巨噬细胞吞噬鸡红细胞试验。并委托细胞室进行靶细胞(YAC-1)传代,进行NK细胞活性试验。
与阴性对照组相比,益生菌粉低、中、高剂量组小鼠脾淋巴细胞增殖能力、抗体积数及NK细胞活性均升高,益生菌粉高剂量组小鼠耳肿胀度、溶血空斑数、吞噬指数及吞噬百分率升高,差异均有统计学意义(
依照《保健食品功能评价方法(2020年版)(征求意见稿)》有助于增强免疫力功能检验方法及结果判定,判定该复合益生菌粉具有增强免疫力功能作用。
108.
Newby Z Lee TT Morse RJ Liu Y Liu L Venkatraman P Santi DV Finer-Moore JS Stroud RM 《Biochemistry》2006,45(24):7415-7428
The enzyme thymidylate synthase (TS) catalyzes the reductive methylation of 2'-deoxyuridine 5'-monophosphate (dUMP) to 2'-deoxythymidine 5'-monophosphate. Using kinetic and X-ray crystallography experiments, we have examined the role of the highly conserved Tyr-261 in the catalytic mechanism of TS. While Tyr-261 is distant from the site of methyl transfer, mutants at this position show a marked decrease in enzymatic activity. Given that Tyr-261 forms a hydrogen bond with the dUMP 3'-O, we hypothesized that this interaction would be important for substrate binding, orientation, and specificity. Our results, surprisingly, show that Tyr-261 contributes little to these features of the mechanism of TS. However, the residue is part of the structural core of closed ternary complexes of TS, and conservation of the size and shape of the Tyr side chain is essential for maintaining wild-type values of kcat/Km. Moderate increases in Km values for both the substrate and cofactor upon mutation of Tyr-261 arise mainly from destabilization of the active conformation of a loop containing a dUMP-binding arginine. Besides binding dUMP, this loop has a key role in stabilizing the closed conformation of the enzyme and in shielding the active site from the bulk solvent during catalysis. Changes to atomic vibrations in crystals of a ternary complex of Escherichia coli Tyr261Trp are associated with a greater than 2000-fold drop in kcat/Km. These results underline the important contribution of dynamics to catalysis in TS. 相似文献
109.
110.
【目的】薇甘菊颈盲蝽是入侵植物薇甘菊的天敌昆虫。CYP4家族基因在专食性昆虫与宿主植物的相互作用中发挥着极其重要的作用,探明其在不同部位的表达情况,可为薇甘菊生物控制提供科学依据。【方法】采用RACE技术克隆薇甘菊颈盲蝽CYP基因,实时荧光定量PCR检测其在不同部位的表达情况。【结果】PmCYP4C1基因全长1713 bp,其中ORF长1500 bp,共编码500个氨基酸,理论分子质量为57.44 ku,无信号肽;与其他昆虫CYP4家族基因的同源性大于40%,与温带臭虫CYP的亲缘关系最近。该基因在雌、雄虫各部位均有表达,且都是足部的表达量明显地高于其他部位;雌、雄虫的表达差异在于雄虫翅膀中的表达量明显地高于触角和残体,但在雌虫中这3个部位的表达量无显著差异,且雄虫翅膀中的表达量显著地高于雌虫,是其2.37倍。【结论】薇甘菊颈盲蝽PmCYP4基因除参与代谢有毒物质外,其主要功能可能是编码与薇甘菊颈盲蝽运动相关的酶。 相似文献