... proposed for the binding of the SRL to the active site of RTA in which the principal difference lies in the conformation of the second ÔGÕ in the target GAGA motif in the 28S rRNA substrate. In one model, ... of RTA resulted in different effects on the activity of RTA. Whereas, one had no effect on the activity of the enzyme (R258A), others reduced activity by one (R213A, R258D, R48A) or by two (R213D) ... hydrogen bonds to be formed between the base G 4 and the sidechain of Asn122. In the second model (Fig. 1B) the structure of the hexanucelotide is, on the whole, unchanged and the majority of the interactions...
Ngày tải lên: 19/02/2014, 12:20
... to the iron(III) of Fe(ToCPP) and Fe(ToCPP))13G10 The second part of our results concerns the binding of imidazole d erivatives on the iron of Fe(ToCPP) either alone in solution or inside the ... this inhibition was due to the binding of the imidazole ligand on the iron atom. In addition, measurement of the kinetic parameters for the oxidation of ABTS by H 2 O 2 catalyzed by Fe(ToCPP))13G10 in the ... (Table 1). The bind- ing 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...
Ngày tải lên: 21/02/2014, 03:20
Tài liệu The Influence of Human Activity on the Environment ppt
... rise. • This leads to disruption of the weather patterns eg drought, floods • Some weeds may thrive on the extra carbon dioxide while other plants are killed Biological Control of Pests • This means ... from the water • This means the fish suffocate and die • This process is called Eutrophication • Raw sewage pumped into rivers has the same effect The Influence of Human Activity on the Environment Benefits ... cars and power stations produces carbon dioxide, sulphur dioxide and other greenhouse gases • carbon dioxide traps heat in the atmosphere and causes the temperature of the earth to rise. •...
Ngày tải lên: 26/01/2014, 10:20
Báo cáo khoa học: Effect of annealing time of an ice crystal on the activity of type III antifreeze protein pdf
... that the TH value reflects the fraction of ice-bound AFPs on the flat ice plane. Indeed, TH increases in proportion with the total concentration of nfeAFP8, as can be seen in Fig. 3A. The fraction ... AFP based on the ‘adsorption–inhibition’ model [3,4]. (A) A convex ice front is created after primary binding of type III AFP onto the flat ice plane. (B) Overgrowth of the convex ice front, giving ... value. (C) Possible secondary ice binding of type III AFP onto the convex ice front during the annealing period (2–3 h). (D) AFPs bound onto the convex ice front narrow the growth area (dashed...
Ngày tải lên: 07/03/2014, 05:20
Báo cáo khoa học: Alizarine derivatives as new dual inhibitors of the HIV-1 reverse transcriptase-associated DNA polymerase and RNase H activities effective also on the RNase H activity of non-nucleoside resistant reverse transcriptases pot
... inhibition potency on the polymerase function; and (c) the K-61 analogue showed a fourfold reduction in its RDDP activity inhi- bition potency. By contrast, when the AQ derivatives were tested on the ... similar conformation (RMS 0.57), on the other hand, in the crystal reported by Pata et al. [30] the NNRTI binding pocket most closely resembles the RT unliganded conformation. Therefore, the AQ ... steric modifications occur. The binding mode of K-49 in the Y181C RT is different, and the contribu- tion of the p–p stacking interaction is lost. Furthermore, the low number of good contacts with...
Ngày tải lên: 22/03/2014, 16:20
Báo cáo khoa học: Effect of heliquinomycin on the activity of human minichromosome maintenance 4/6/7 helicase pdf
... both the ini- tiation and elongation of DNA replication [13], and these proteins migrate on the genome together with the replication forks [14,15]. One of the intricacies related to the function ... solution (0.4 lL) containing or lacking heliquinomycin was added to the reaction mixture. The final con- centrations of heliquinomycin added to the reaction mixture are indicated at the top. The ... DNA was considered to be 100% in the control reaction mixture lacking heliquinomycin, and the proportions in the mixtures containing heliquinomycin were cal- culated in relation to the control...
Ngày tải lên: 23/03/2014, 04:21
Báo cáo khoa học: Effect of magnesium ions on the activity of the cytosolic NADH/cytochrome c electron transport system pptx
... Fig. 1 on the oxidation of exo- genous NADH as the expression of the activity of the complete system. Discussion The data presented provide new insights into the role of magnesium ions in the permeability ... provides direct evidence that, in these latter conditions, the addition of magnesium mimics the results obtained with the addition of cyto-c, the only difference being that the potential is lower and ... mitochondria, activates the oxida- tion of extramitochondrial NADH and the generation of a membrane potential, both linked to the activity of the cytosolic NADH/cyto-c electron transport pathway. The...
Ngày tải lên: 23/03/2014, 06:20
Báo cáo khoa học: The ‘pair of sugar tongs’ site on the non-catalytic domain C of barley a-amylase participates in substrate binding and activity potx
... agreement with the reduced DMA of the AMY1 Y380A ‘sugar tongs’ mutant, these effects may stem from allosteric regula- tion. The mutational analysis of the ‘sugar tongs’ in barley AMY1 explored the role ... This is the first demonstration of a function for a C domain from the large GH clan-H. The work contributes to the unraveling of the molecular basis of multivalent enzyme–polysaccharide interactions. ... connects b5 and a5 of the catalytic (b ⁄ a) 8 -barrel at the end of the aglycon-binding area of the active site cleft. Earlier, significant deviation was found in this region between the backbone...
Ngày tải lên: 23/03/2014, 07:20
Báo cáo khoa học: The antibiotic activity of cationic linear amphipathic peptides: lessons from the action of leucine/lysine copolymers on bacteria of the class Mollicutes doc
... by spreading on agar plates cells treated for 2 h with different peptide concentrations. The minimal lethal concentration was defined as the lowest peptide concentration capable of killing 99% of the cells ... R, No activity at concentrations £ 100 l M . Ó FEBS 2003 Antibacterial activity of LK peptides (Eur. J. Biochem. 270) 2209 of action based upon the invasion of the outer membrane leaflet by the ... flat orientation should thus be considered the most stable one for LK peptides, even if other orientations are possible (see below). As suggested by the ÔcarpetÕ model, aggregation on the membrane...
Ngày tải lên: 23/03/2014, 17:21
Báo cáo khoa học: On the mechanisms of bananin activity against severe acute respiratory syndrome coronavirus pptx
... molecular interface in the case of the former helicase. Further- more, the absence of the S259 OH group in the mutated viral enzyme prevents the formation of one hydrogen bond with bananin, accounting for the reduced ... accession number AY304495) on fetal rhesus monkey kidney cell line FRhK-4 in the presence of high concentrations of this adamantine derivative. The half maximal effective concentration of bananin on these ... protein, only second- ary structure predictions can be obtained, limiting a detailed structural interpretation of the functional roles of A68V and R124W mutations. blast analysis on the 19 complete...
Ngày tải lên: 28/03/2014, 23:20
Báo cáo khoa học: Effects of a tryptophanyl substitution on the structure and antimicrobial activity of C-terminally truncated gaegurin 4 doc
... tryptophanyl substitution at position 16 on the biological activity was confirmed for the native GGN4. Consistent with the results of the C-terminally truncated GGN4, the D16W substitution in the native GGN4 ... contrast, neither the D16F nor K15W substitution of the D 24)37 GGN4 allowed such a dramatic recovery of activity. In addition, the D16W substitution of the native GGN4 significantly enhanced the ... that the D16W substitution of D 24)37 GGN4 contributed to the restoration of the antimicrobial activity, at least by changing its structure. In order to elucidate the structure-function relationship of...
Ngày tải lên: 31/03/2014, 09:20
Báo cáo Y học: Effect of coenzymes and thyroid hormones on the dual activities of Xenopus cytosolic thyroid-hormone-binding protein (xCTBP) with aldehyde dehydrogenase activity potx
... T 3 when NAD + concentration was varied within the reaction mixture. The reaction was performed at 24 °Cwith5lg of xCTBP/xALDH1. The concentration of retinal was 30 l M and the concentrations of T 3 were ... the inhibition of xCTBP/xALDH1 by T 3 when ret- inal concentration was varied within the reaction mixture. The reaction was performed at 24 °Cwith5lg of xCTBP/xALDH1. The concen- tration of NAD + was ... T 3 was examined by variation of NAD + concentration within the reaction mixture. The K m value, 9 l M , was independent of the concentration of T 3 , but the V max value decreased from 0.18 to...
Ngày tải lên: 31/03/2014, 21:21
SYNTHESIZE AND INVESTIGATE THE CATALYTIC ACTIVITY OF THREE-WAY CATALYSTS BASED ON MIXED METAL OXIDES FOR THE TREATMENT OF EXHAUST GASES FROM INTERNAL COMBUSTION ENGINE
... 2 CO C : the concentration (%V) of CO 2 in the flow after reaction CO C : the concentration (%V) of CO in the flow after reaction 2 CO C : the concentration (%V) of CO 2 in the flow after reaction ... among the most frequently used techniques in catalysis. It yields information on the elemental composition, the oxidation state of the elements and in favorable cases on the dispersion of one ... adsorption. In certain cases the rate-determining step is the chemisorptions of oxygen [97]. 1.4.2 Mechanism of the oxidation reaction of carbon monoxide The catalytic oxidation of CO on the surface...
Ngày tải lên: 12/05/2014, 17:14
Báo cáo hóa học: " On the Enhanced Antibacterial Activity of Antibiotics Mixed with Gold Nanoparticles" pot
Ngày tải lên: 22/06/2014, 00:20