nmr in structure elucidation of flavonoids

... contain lysine, arginine or histidine The X-ray structures of several proteins containing PEST sequences have been determined, but in each case the electron density of the PEST sequence is missing ... of the JAK2 kinase domain Mutagenesis studies have shown that a number of residues [3,4,25,28], important in binding phosphotyrosine-containing peptides or proteins, lie outside the SH2 domain ... duration of the cellular response to cytokine signalling will be determined, in large part, by the rate of turnover of the SOCS proteins Expression of the SOCS proteins is induced directly by STAT binding...

Ngày tải lên: 16/03/2014, 14:20

... the increased rate of 13C label incorporation into the C6 position of glycogen in the ADM group is indicative of activated 6-phosphofructo-1-kinase, which can lead to increased 13C labeling at ... start of glucose infusion For the calculation of glycogen C6 changes, data acquired within h of the start of the glucose infusion was not included to avoid any in uence of transient changes in the ... Such a mechanism can lead to increases in labeling of glycogen C6 even in the presence of decreased activity of the indirect pathway, provided that the increase in glycolytic flux exceeded the...

Ngày tải lên: 17/03/2014, 17:20

... lacking of fragment ions corresponding to the presence of a reducing end Rha or a nonreducing end Rha of considerable intensity Thus, the absence of fragment ions corresponding to losses of reducing ... nonreducing end of the acceptor chain at the cytoplasmic face [20] In some cases a single enzyme catalyses the formation of more linkages and this, of course, poses difficulties for the maintenance of ... occasion of his 70th birthday A M is grateful to Prof M Adinolfi for the kind gift of D-Fuc3NAc The 800 MHz spectra were obtained using the Varian Unity Inova spectrometer of the Danish Instrument...

Ngày tải lên: 31/03/2014, 09:20

... microprofiles of NH4+, NO2-, and NO3- in an autotrophic nitrifying biofilm that was initially fed with enrichment culture of nitrifying bacteria (bioaugmented biofilm) This bioaugmented biofilm ... were performed In situ hybridization of vertical biofilm thin sections clearly indicated that the numbers of probe NEU-stained NH4+-oxidizing bacteria (i.e., Nitrosomonas marina-lineage, Nitrosomonas ... distributions of in situ nitrifying activities were determined The relationship between the spatial organization of nitrifying bacterial populations and the in situ activity of these populations within...

Ngày tải lên: 05/09/2013, 08:40

... also marked point process models allowing a continuous jump spectrum However, introducing a continuous jump spectrum also introduces a possibly in nite number of independent sources of randomness ... fact remains true also in bond markets when marked point processes with continuous mark spaces, i.e an in nite number of sources of randomness, are allowed? One of the main results of this paper ... self-financing portfolio if and only if certain integral equations of the first kind (the “hedging equations”) have solutions Furthermore, the integral operators appearing in these equations (the “hedging...

Ngày tải lên: 16/02/2014, 02:20

... K, Hoffmann S, Bauer F, Friedrich U, Kardinal C, Feller SM, Biesinger B & Sticht H (2002) Structural investigation of the binding of a herpesviral protein to the SH3 domain of tyrosine kinase ... respectively retained in the centre of the interhelical linker and at the C-terminus of micelle-associated VpUcyt Position of VpUcyt relative to the micelle NMR signal intensities of individual VpUcyt ... phosphorylation of two serine residues in the cytoplasmic domain of HIV-1 VpU J Pept Sci 14, 804–810 Henklein P, Kinder R, Schubert U & Bechinger B (2000) Membrane interactions and alignment of structures...

Ngày tải lên: 18/02/2014, 06:20

... subunits) c Unless otherwise indicated, Ki values for inhibition of epibatidine binding are shown; B, inhibition of a-BTX binding d Indicates cases where Kd values were obtained from oocyte-expressed ... (2001) Crystal structure of participate in the formation of EpI-resistant a7 receptors, or an ACh-binding protein reveals the ligand-binding domain of that the functional properties of the nAChR ... microdomains within the same binding site [35] The proline residue in position 6, which is conserved in all other a-conotoxins, appears to be the major determinant of the abilities of ImI and...

Ngày tải lên: 19/02/2014, 12:20

... responsible for binding and proper orientation of the aminopyrimidine ring, are conserved in all ThDP-dependent enzymes One of these, the hydrogen bond between the N1¢ atom of the pyrimidine ring of ThDP ... presence of DNA-binding proteins involved in regulation of the gene expression of indole-3pyruvic acid decarboxylase, a key enzyme in indole-3-acetic acid biosynthesis in Azospirillum lipoferum FS Biosci ... structure Binding of the cofactors ThDP and Mg2+ The homo-tetrameric IPDC binds four molecules of the cofactors ThDP and Mg2+ The ThDP binding sites are located in narrow clefts at the interfaces...

Ngày tải lên: 20/02/2014, 11:20

... differences in chemical shifts for the remaining residues Structure determination The existence of two distinct sets of resonances for the minidomain allowed the determination of two families representing ... Effect of mutations in the minidomain on stop codon specificity Superposition of the NMR structure of the human C-domain on the full-length crystal structure of eRF1 reveals that the minidomain is ... minidomain, owing to the increased mobility of this protein fragment The NMR structure of the human C-domain in solution reported here therefore represents the first view of this minidomain Moreover,...

Ngày tải lên: 06/03/2014, 11:20

... domains, respectively, and appear to stabilize their protein scaffolds, allowing the proper positioning of the residues involved in PLP binding, substrate binding and modulation of the cofactor’s ... value determined from the amino acid sequence (45 320 Da) Measurement of the Kd of PLP binding equilibrium PLP binding equilibria were analyzed taking advantage of the protein intrinsic fluorescence ... 139 Role of hydrophobic contacts in serine hydroxymethyltransferase to bind PLP In this intermediate, the N-terminus and an inter-domain segment remain exposed to solvent In the following, slow...

Ngày tải lên: 07/03/2014, 03:20

... karst cave potential exploration for tourism development in Ninh Binh province” Morphostructure features of 36 caves, including famous caves in Yen Mo-Tam Diep area were studied and described here ... characters also have an influence in forming this relief, especially for line valleys Two kinds of valleys are most spread in study area: a symmetric closed valley and line karst valley Their ... and drain water system (Fig.3) This kind relief is not spread well in study area, it presents only in Ninh Hai, Dong Son Village and in ward Nam Son, TamDiep - Karst dry valley 145 forming karst...

Ngày tải lên: 14/03/2014, 15:20

... sequences show the coordinate of nucleotides and amino acids in corresponding lines The full-length cDNA encoding the putative GIH of P monodon was composed of 861 nucleotides containing a 5¢-UTR (93 ... Expression of Pem-GIH in the abdominal nerve cord of adult female shrimp at and h after incubating without ()) or with (+) GIH-dsRNA or GFP-dsRNA as indicated (C) Expression of Pem-GIH in the abdominal ... that in control shrimp The increase in the ratio of Vg to actin transcripts in the GIH-depleted background suggested that functional knockdown of Pem-GIH led to the induced expression of Vg in...

Ngày tải lên: 23/03/2014, 07:20

... determine the in uence of the N-terminal region of TTR on the binding to thyroid hormones, the construction of chimeric recombinant TTRs containing variations in structure of the N-terminal region ... PAGE, indicating that the recombinant TTRs as tetramers Analysis of binding to retinol-binding protein and thyroid hormones showed that the recombinant TTRs retained its function as binding protein ... N-terminal structure of TTR and binding of thyroid hormones In one of these TTRs, the crocTTR N-terminal region was replaced by the N-terminal region of human TTR (whereas crocTTR preferentially binds...

Ngày tải lên: 23/03/2014, 10:21

... To determine the amplitude of the toxin-induced slow inactivation, we subtracted the control traces from the traces recorded in the presence of the toxin The amplitude of these toxin-induced currents ... showing the slow toxin-induced component (s) (Materials and methods) Insets: left, control inward current at mV (CON) and in the presence of 2.8 lM Cn12; right, the slowly inactivating toxin-induced ... the S5–S6 segment from domain I of mammalian channels may in uence the binding of nonpositively charged Na-ScTxs, disfavouring their binding because of the absence of primary electrostatic attraction...

Ngày tải lên: 23/03/2014, 12:20

... III, again perhaps indicating that steric interference of the two chains precludes coincident expression of both It is noteworthy that the majority of SiallNnT-containing glycoforms contain two ... (Hep III) of the inner core [11] Interestingly, following mutation of the sialyltransferase gene (lic3A) responsible for addition of Neu5Ac to the lactose moiety in this strain, creating the double ... sialylated glycoform The structure of the sialylated glycoforms of the O-deacylated LPS of H in uenzae strain RM118 and mutants causing sequential truncations from Hep III are illustrated in Fig DISCUSSION...

Ngày tải lên: 23/03/2014, 21:21

... assembly in the presence of metals is unlikely to involve the same intermolecular interactions as within fibrils, as removal of the metals causes dissociation into monomers instead of the continued ... Error bars indicate the experimental uncertainty of the measurements observed between the Cu2+-induced and Zn2+-induced aggregates, reflecting the differences in metal-binding properties of Ab [26,30,33–35] ... protection This is reasonable, as metal binding occurs within the first 14 residues, inducing a low degree of secondary structure [33,50] However, the remaining parts of both Ab(1–40) and Ab(1–42) still...

Ngày tải lên: 30/03/2014, 01:20

... 1991,Schrader et al 2001) Of particular health concern is the incidence of esophageal cancer in Linxin, China The etiology of this cancer was connected with the contamination of cereal grains with A alternata ... establishment of a reproducible system which enables the elucidation of all important influences on mycotoxin production in A alternata For optimal reproducibility and comparability of single experiments ... curve fittings of TA and AOH were ≥ 0.99 and of AME ≥ 0.97 The maintained parameters for the fittings are displayed in Table Both nitrogen sources and glucose were consumed completely during the...

Ngày tải lên: 20/06/2014, 23:20

... (Department of Chemistry of Medicinal Natural Products and Key Laboratory of Drug Targeting of Education Ministry PRC, West China College of Pharmacy, Sichuan University) for helpful assistance in NMR ... and infrared analysis of the samples was obtained by grinding a mixture of polysaccharide with dry KBr and then pressing in a mold Spectra were run in the 4000–400 cm−1 region 2.8 Scavenging ... hydroxyl radicals The ability of the TMP-A to scavenge hydrogen peroxide was determined according to the method of Smirnoff and Cumbes [17] The percentage of scavenging of hydrogen radicals was calculated...

Ngày tải lên: 28/06/2014, 11:20

... changes occurring in beech seedlings induced by the increase of relative irradiance MATERIALS AND METHODS In 1994 beech seedlings were planted (2.5 m × 2.5 m) in the understory of a forty-year ... Irradiance level, estimated from light index increased in the understory in the two years after the thinning of pine trees The increase in stomatal density, blade In the present study the SLM differences ... changes produced on leaf anatomy and SLM in underplanted beech seedlings in response to overstory thinning of a Pinus sylvestris stand and the subsequent increase in the relative irradiance A different...

Ngày tải lên: 08/08/2014, 14:20

... substitution of an arginine by a histidine (R101H) In affected members of both families there was no MMP-2 activity detected in serum by gelatin zymography, in contrast to measurable levels in unaffected ... disruption of the MMP13 gene The strategy employed involved the deletion of the critical zinc-binding region in the catalytic domain that resulted in markedly decreased transcription of the MMP13 ... demonstration of a spontaneous mutation in a MMP gene resulting in a human disease We look forward to descriptions of mutations and the resultant phenotype in other MMP genes geting mutations in Col1a1...

Ngày tải lên: 09/08/2014, 01:21