biological activity of the natural products

... investigated the biological activity of MIH and CHH during precisely timed stages of the moult cycle of Carcinus to determine changes in: (a) potency of these peptides in repressing ecdysteroid synthesis; ... levels in the XO, and peptide levels in the SG during these significant stages of the moult cycle, as these are of fundamental importance with regard to the currently accepted model of moult control ... secretory products of the YO, ecdysone and 25-deoxyecysone Inhibition of 3-dehydroecdysone synthesis was not measured, but this is a minor secretory product of Carcinus YO [11] Loss of sensitivity of...

Ngày tải lên: 21/02/2014, 00:20

... increasing the receptor affinity and selectivity of peptide ligands [13,14,27] The Ala-scan of OP has revealed that the side chain of each residue is required for the full activity of the peptide [12] These ... vicinity of cultured cells provoked a wave of calcium in the cytoplasm of astrocytes (Fig 3A) while ejection of culture medium alone had no effect (Fig 3B) Comparison of the amplitude of the response ... compared to the other amide protons The 3JNH-Ha coupling constants for the amide protons of cyclo128 OP were measured from the 1D 1H-NMR spectrum (Table 1) The 3JNH-Ha coupling constants of the three...

Ngày tải lên: 24/03/2014, 04:21

... Disclaimer Title of Thesis/Dissertation: Investigating the Biosynthetic Pathway of Polyacetylenic Natural Products in Fistulina hepatica and Echinacea purpurea For the degree of Master of Science I ...  background of  these  interesting  properties    Nevertheless, the biological   activities of  this  class of  compounds  indicate the  significance  for  research  in the  area of   acetylenic ... biosynthesis   largely   occurs   either   in   the   chloroplasts   or   the   stroma of  plastids,  whereas  in  most  other  eukaryotes  biosynthesis  occurs  in the  cytosol   [3]     The...

Ngày tải lên: 24/08/2014, 11:28

... anticancer activity However, it is still unclear whether the anticancer activity of the PR domain is due to its methyltransferase activity or the interaction 166 with the PRB motif Further studies ... suppressor activity The PR domain of RIZ1 possessed anticancer activity from the transfection studies This finding leaves us an important question on the roles the other structural components of RIZ1 ... over the progression of cancer; and the second question is whether the PR domain alone possesses anticancer activity In this study, we quantitatively analyzed the mRNA expression level of RIZ1...

Ngày tải lên: 25/10/2012, 11:15

... value of LMWC is due to the release of GlcNAc and GlcNAc-rich oligomers as some of the products An examination of DA values indicates that the total DA of the products is equal to that of native ... of chito-oligomers as one of the products and a drastic decrease in molecular mass of chitosan indicates an endo-type activity of pronase Addition of hexosaminidase (specific for the release of ... depends on the conformation of the primary -OH group (C6) in a favorable orientation [33] The shift of the same to 1458 cm)1 in the LMWC would probably indicate a change in the environment of primary...

Ngày tải lên: 19/02/2014, 12:20

... with the higher inhibitory activity of the cEL peptide and the very low inhibitory activity of the cYT peptide compared to other peptides The flanking residue of the b-turn, i.e Tyr3 of the cVY ... Ser5 The rmsd of the backbone atoms of the 12 structures in the chosen family was compared with the average structure in the same family It was found that the rmsd of all the backbone atoms in the ... [38] Analysis of the crystal structure of CD2 revealed that on either side of the binding surface of CD2, there are b-turns which stabilize the b-strands Thus, we hypothesized that these b-turns...

Ngày tải lên: 19/02/2014, 13:20

... observed neither a change of the excitation nor of the emission uorescence spectra in the presence of any of these H4-H5 loopGST ể FEBS 2004 Mapping of ATP and pNPP binding sites of the Na pump ... F is the normalized uorescence, [P] is the concentration of TNP-ATP, [E] is the concentration of the enzyme, c is the enhancement of uorescence intensity of the bound probe relative to the free ... N-domain is due the formation of an hydrogen bond of the NO2-group of pNPP with the amino group of N398 The hydrophobicity of the binding pocket is achieved by W411 and L414 The phosphate group...

Ngày tải lên: 19/02/2014, 16:20

... Fragments of HSQC and HMBC spectra of compound Labels illustrate assignment of the amide linkage between the amino group of Asp and the carboxyl group of GalA residue E Scheme The structures of oligosaccharides ... branching information [31] The charge state of a fragment ion is then identified by using the isotope profile, owing to the high resolution provided by the TOF mass analyser The product-ion spectrum ... 1436.42, owing to the loss of the branching xylose residues M and O, and of GlcA residue L The remaining linear sequence, consisting of K-B-F-I-D-N-Q, was confirmed by the observation of Ó FEBS 2004...

Ngày tải lên: 19/02/2014, 16:20

... important for the GABA transport activity 1-Deoxymannojirimycin inhibits the GABA-uptake of GAT1 In order to gain further insight into the role of the terminal structures of the N-glycans of GAT1, ... on the plasma membrane The activity of GABA-uptake by NNN was set at 100% The values represent the mean ± SEM of five separate experiments is similar to that of NNN containing N-glycans of the ... measurement of the activity of GABAuptake, an aliquot of the stable CHO transfectants was used for GABA-uptake assay, and another aliquot was used to determine the quantity of plasma membrane proteins of...

Ngày tải lên: 19/02/2014, 17:20

... answer the question whether the cubic structure observed is of the ÔnormalÕ (right side out) or the inverted type, the geometry of the molecule with its bulky headgroup is in favor of the former ... headgroup conformations The determination of the b«a gel-to-liquid crystalline phase transition of the acyl chains from the evaluation of the symmetric stretching vibration of the methylene groups ... to form a solid gel in the presence of minute amounts of endotoxins The comparison of LPS and MfGl-II in the LAL assay shows, as expected, activity of LPS in the range of down to 10 pgÆmL)1,...

Ngày tải lên: 21/02/2014, 00:20

... (Table 1) The binding of the ®rst CN± ligand to the iron was thus more easy in the hydrophobic binding pocket of the antibody than the binding of the second one, most probably because of the steric ... shown) This shows that the binding of the two cyanide ligands to the iron atom of 13G10±Fe(ToCPP) actually occurred inside the binding pocket of the antibody The value of the dissociation constant ... two-thirds of the porphyrin moiety was inserted in the antibody pocket, three of the ortho-carboxylate substituents of the meso-phenyl rings being recognized by the side chains of amino acids of the...

Ngày tải lên: 21/02/2014, 03:20

... consisted of a linker (Glc-Kdo2)-lipid A structure The phenotype of this mutant was examined to investigate the roles of different moieties of the LOS molecule in biological activities of the M catarrhalis ... construction of the lgt3 mutant in M catarrhalis O35E Large arrows represent the direction of transcription; the site of the transposon insertion identified in the O35E is denoted as EN:TN, and the location ... groups Among the other ions m ⁄ z of 2654.8, 2694.8 and 2717.4 indicates the presence of the anhydro form and mono- and di-sodiated form of the molecular ion 2672.8 (Fig 4A) Among other characteristic...

Ngày tải lên: 07/03/2014, 05:20

... processes We then addressed the question as to whether high SUT2 gene dosage suppresses the slow growth phenotype of Dgpa2 Dras2 cells by increasing PKA activity Low activity of the PKA pathway ... final D600 of (± 0.5) A fraction of these cultures (equaling approx 50 mg of wet weight cells) was collected to determine the level of storage carbohydrates after entry of stationary phase The remainder ... [24] which in the wild type requires high PKA activity These consequences of PKA-pathway activity were tested subsequently in order to examine the influence of high copy SUT2 on PKA activity We...

Ngày tải lên: 07/03/2014, 15:20

... verified the binding of pyrrhocoricin to the E coli DnaK fragment and the lack of a sequence analogous to that of S aureus (Fig 6) To study the interaction of the antibacterial peptide and the synthetic ... while the N-terminus served as the pharmacophore and hence the interactive domain with the bacterial target protein, the C-terminal half aided the delivery of the pharmacophore into the interior of ... molecule of the unlabeled partner, and while the concentration of the unlabeled larger molecule determines the association constant, the concentration of the labeled partner determines the fluorescence...

Ngày tải lên: 08/03/2014, 10:20

... weak The peptide is further stabilized at the active site by the interaction of the N-terminal amine of the P1 residue with a carboxylate oxygen of Asp273 (Asp366), the carbonyl oxygen of the ... with the role of Lys282 in PepA (blLAP Lys262) in binding of the carboxyl oxygen of the P1 residue and stabilization of the gem-diolate transition state The Ala substitution mutant (K354A) of the ... influence the binding of the zinc-bridging water and/or ability of Zn2 and Zn1 to bind the N-terminal amine and carbonyl oxygens of the P1 residue of the substrate, respectively The replacement of Asp347...

Ngày tải lên: 08/03/2014, 23:20

... favor of the MG state The T domain favors the interaction of the C domain with the membrane, because it brings the C domain in its MG state into the vicinity of the bilayer, the MG state of both ... binding of T), at a pH higher than when it was isolated The T domain facilitated the insertion of the C domain in the membrane To better characterize the environment of the Trp residues of the C ... each of the C and T domains influences the membrane interaction and the associated conformational changes of the other domain We compared the pH sensitivities and the membrane interactions of the...

Ngày tải lên: 14/03/2014, 22:20

... marked with * (B) Southern analysis of the input constructs The products of the restriction enzyme digestions are marked as those in the 293T-cell figure (Note the absence of a 3748 bp product.) ... bone marrow [10] and several other organs [20] However, the main host cells and the target organs of this virus are still undefined The study of the biological functions of TTV is particularly challenging ... resemble the other known TTV types: a TATA-box and a poly(A) sequence flanking the coding region, and a GC-rich area of 107 bp located in the noncoding region The biological activity of our full-length...

Ngày tải lên: 16/03/2014, 05:20

... in the presence of excess phytic acids, since phytic acid is not a perfect mimic of the headgroup of PtdIns4P Although PEX1-ND is recruited to the liposomes in the presence of a large excess of ... representation of the binding of the N-terminal domain (ND) of PEX1 to the peroxisomal membrane PEX1 is predicted to interact with the PEX6 portion of AAA domains PEX1-ND binds to the peroxisomal ... membranes in vivo [22] On the other hand, colocalization of VCP and PtdIns-4-kinase IIa on the buoyant subfraction of ER-derived membrane was observed [66] The ND of VCP, rather than the D1 or D2 domains,...

Ngày tải lên: 16/03/2014, 12:20

... indicated by the numbers on the right side The migration of the protein markers is indicated by pencil marks on the membrane The arrow indicates the position of the wild-type and N130D variants of human ... percentage of the initial activity of the corresponding fully activated species Fig 4, whereas dialyzed wild-type species expressed about 50% of full arginase activity in the absence of added Mn2+, the ... difference was the shorter extension of a loop located at the entrance of the active site cleft The arginase loop (residues 126–143 in the sequence of human liver arginase) contains Asn130 and other residues...

Ngày tải lên: 16/03/2014, 12:20

... reflect the poorly defined nature of the first turn of the a-helix due to the lack of hydrogen bonds to their NH protons Comparison of the observed NH chemical shifts of A4K14-citropin 1.1 with the ... antibacterial activity of membrane active peptides, suggests that the anticancer activity is also due to penetration and disruption of the membranes of the cancer cells The selectivity of these peptides ... of residues from the N-terminal end of the citropin system destroys the activity against nNOS, whereas loss of activity is not so marked when residues are removed from the C-terminal end of the...

Ngày tải lên: 17/03/2014, 09:20