b general synthesis of macrocyclic iron ii metal complexes

... constant in Hz s Singlet d Doublet t Triplet dd Doublet of doublets ddd Doublet of doublets of doublets dt Doublet of triplets td Triplet of doublets m Multiplet br Broad Mass Spectrometry (MS) ... ruthenium (II) and iron( II) metallomacrocycles Curriculum Vitae 311 323 v Abbreviations Abbreviations General Ant A sol CH3CN: saturated aqueous KNO3: H2O in 14:2:1 ratio Bipy 2,2′-Bipyridine Bbipy-(GalNHAc) ... characterisation of the mononuclear iron( II) and ruthenium (II) complexes formed with L1-L9 Chapter describes the synthesis and characterisation of the mononuclear cobalt (II) complexes formed...

Ngày tải lên: 02/07/2014, 13:33

... 2.6 94 Number of protein atoms Number of solvent molecules Number of DHAP ⁄ Zn atoms Number of glycerol atoms R-factor (%) R-free (%) ˚ rmsd bond lengths (A) rmsd bond angles (°) ˚ Mean B- factor ... catalysis, not only because it contributes to Zn2+ coordination but also because of its direct involvement in substrate binding (Fig 3A ,B) Indeed, as detailed above, Asp291 stabilizes DHAP through ... onto the substrate, as observed in other members of the amidohydrolase superfamily [24,25] However, as no structure of complexes with either the substrate, product or inhibitors had been reported,...

Ngày tải lên: 18/02/2014, 06:20

... respectively Plasmid pUSI2E(bG) was digested with NdeI and BglII Resulting 600-bp NdeI-BglII fragment was inserted into the NdeI-BglII region of pET1 9b to produce pET1 9b( H6bG) A pair of synthetic oligonucleotides, ... that the bound cobalamin is actually cob (II) alamin Substrate- and K+-binding sites Substrate propane-1,2-diol and the essential cofactor K+ are bound inside the TIM barrel of the a subunit (Fig ... a substrate, and K+, an essential cofactor, are bound inside the barrel The active site-cavity is covered by the corrin ring of cobalamin that is bound on the interface of the a and b subunits...

Ngày tải lên: 21/02/2014, 03:20

... Yoshizawa et al Structure of Bg7S, a XEGIP-like protein of soybean Structured digital abstract l Bg7S binds to Bg7S by x-ray crystallography (View interaction) l Bg7S binds to Bg7S by cosedimentation ... dimer at both weakly acidic pH (6.0) and weakly basic pH (8–9) Table DASA in dimer formation The DASA of the AB dimer is defined as [(ASA of A) + (ASA of B) ) (ASA of AB dimer)] ⁄ The number of water ... disulfide bonds supposedly stabilize the three-dimen- Structure of Bg7S, a XEGIP-like protein of soybean sional structure of Bg7S The Cys209–Cys418 bond seems to be significant for stabilization...

Ngày tải lên: 14/03/2014, 23:20

... consecutive backbone residues with Xyl side chains and a fourth unbranched Glc residue, and XXGG-type xyloglucans have two consecutive branched backbone residues and two unbranched backbone residues ... tetrasaccharide backbone (XXXG) For many years, endo -b- 1,4-glucanases have been considered to be a subgroup of cellulases (EC 3.2.1.4) Recently, however, it has been clarified that some endo -b- 1,4glucanases ... is conceivable that XEG and OXG-RCBH recognize the backbone of the b- 1,4-glucan in a similar manner, despite their differences in substrate specificity and mode of hydrolysis Two notable differences,...

Ngày tải lên: 23/03/2014, 05:22

... structure of the class C b- lactamase TAE4 from Pse fluorescens The important residues of the active site are labeled The unobserved loop is indicated by the black box ˚ (Protein Data Bank code ... 2008 FEBS C Michaux et al be partly responsible for the larger flexibility of the cold b- lactamase and for its ability to hydrolyze large substrates Both psychrophilic b- lactamases have fewer ion ... cold-adapted enzymes may be characterized by a decreased number of disulfide bonds, an increased number of glycine residues, a reduced apolar fraction in the core, higher accessibility of the active site,...

Ngày tải lên: 23/03/2014, 07:20

... membrane which is directed from the inside to the outside of the lipid bilayer The phosphatase may be regulated by the reversible binding of TLP40 to a trans-membrane protein, which could be ... helical bundle will become accessible for interaction with the thylakoid trans-membrane phosphatase Phosphatase binding of AtCyP38 inhibits the 111 dephosphorylation process by phosphatase Binding of ... This is probably of great significance in its interaction with other proteins A B Helical bundle β-barrel Helical bundle C Helical bundle Active site Figure 36 Surface charge features (blue for...

Ngày tải lên: 14/09/2015, 17:50

... that salt bridges can be stabilizing or destabilizing Due to systemic protein flexibility, reflected in small-scale side-chain and backbone atom motions, salt bridges and their stabilities fluctuate ... act on one type of substrate, being glucose residues linked through an α–1,1, 1,4, or 1,6 glycosidic bond The members of this family share a number of common characteristics but at least 21 different ... elements of AmyA are shown on top of the AmyA sequence Surface accessibility of residues is shown at the bottom of the aligned sequences The most accessible residues are shown in dark blue and buried...

Ngày tải lên: 16/09/2015, 08:31

... determined by the nature and position of substituents on the phenolic ring of the substrate Second, the redox potential (E°) of the substrate must be low enough, as the rate of the reaction has been ... factor contributing to the rate of substrate oxidation (Table 1) The kinetics of substrate oxidation by laccases has also been shown to be pH-dependent [47] At higher pH values, phenolic substrates ... started by addition of substrate, and the rate of substrate oxidation was measured by monitoring the change in absorbance over All of the measurements were performed in duplicate, with eight substrate...

Ngày tải lên: 14/02/2014, 18:20

... NLS binding J Biol Chem 275, 21218–21223 Kobe B (1999) Autoinhibition by an internal nuclear localization signal revealed by the crystal structure of mammalian importin alpha Nat Struct Biol ... MR, Corbett AH & Hodel AE (2001) Dissection of a nuclear localization signal J Biol Chem 276, 1317– 1325 Fontes MR, Teh T & Kobe B (2000) Structural basis of recognition of monopartite and bipartite ... signals by karyopherin alpha Structure 8, 329–338 22 Fontes MR, Teh T, Jans D, Brinkworth RI & Kobe B (2003) Structural basis for the specificity of bipartite nuclear localization sequence binding by...

Ngày tải lên: 14/02/2014, 19:20

... structures of apo (green), Mn-bound (magenta) and Fe-bound (cyan) ApeSODs are superimposed and shown as a stereo view The metal cofactor of the Mn-bound form is indicated by a ball (B) Tetramer ... involved in the adaptation of proteins to extreme environments Biochim Biophys Acta 1343, 23–30 Meier B, Barra D, Bossa F, Calabrese L & Rotilio G (1982) Synthesis of either Fe- or Mn-superoxide ... around the active site of ApeSOD is independent of the presence of a metal cofactor Figure 3D shows the superimposition of the active site structures of apo, Mn-bound and Fe-bound ApeSODs The most...

Ngày tải lên: 14/02/2014, 22:20

... Content of the asymmetric unit Number of nonhydrogen atoms Number of protein molecules Number of water molecules Number of glycerol molecules Number of sodium ions Number of magnesium ions Number of ... N-terminus of a helix L The orientation of this helix allows substrate binding by hydrogen bond formation, and its dipole facilitates substrate binding as well The hydrogen bond between the backbone ... is a single hydrogen bond between the substrate, phytate and the backbone of PhyK involving Asp291 In the structure of phytate bound to AppA, this hydrogen bond is also observed and, moreover,...

Ngày tải lên: 16/02/2014, 09:20

... interaction of the two b- barrels, formation of the catalytic machinery and structures required for binding of the main chain of the substrate peptide and proper positioning of the scissile bond with ... nature, but also in the flexibility of the different members of the HAT ⁄ HAT-like ⁄ DESC subfamily In conclusion, it is possible to summarize that not only the members of the four TTSP subfamilies ... Shkl||Fobs| ) k|Fcalc|| ⁄ Shkl|Fobs| R-factor ¼ ShklTest||Fobs| ) k|Fcalc|| ⁄ ShklTest|Fobs| a 2158 b Free Szabo R, Wu QY, Dickson RB, Netzel-Arnett S, Antalis TM & Bugge TH (2003) Type II transmembrane...

Ngày tải lên: 19/02/2014, 00:20

... protein encoded by bc1534 is classified as a LmbE-related protein and hereafter will be referred to as BcZBP (B cereus zinc-binding protein) The N-terminal part of BcZBP (residues 7–124) belongs to ... oligomerization of BcZBP, the differences in C-terminal regions between BcZBP and MshB could account for the absence of oligomerization in MshB [8,9] As noted above, the final size and shape of the active ... likely Crystal structure of BcZBP from B cereus Based on the above common features, we suggest that the catalytic mechanism of BcZBP is probably similar to those proposed for MshB and LpxC This hypothesis...

Ngày tải lên: 19/02/2014, 00:20

... residue, probably resulting from different scaffolds of the inhibitors Structures of PRK with inhibitors or sub- Fig Stereo plot illustrating inhibitor binding in subtilases The binding loop of chymotrypsin ... the bottom of the S1 pocket This bridge can be considered to be involved in the stabilization of the region which is stabilized by calcium (Ca3) in PRK (residues 200 and 175–177) Both disulfide bridges ... inhibitor II (CI2) in complex with subtilisin BPN (cyan, PDB 2sni), the inhibitor fragment of lactoferrin in complex with PRK (green, PDB 1bjr), a hepta-peptide in complex with PRK (yellow, PDB...

Ngày tải lên: 19/02/2014, 07:20

... conservation of charged residues is comparable with the overall homology of these structures, being in the range of 30–40% Table Comparison of structural features of 1SH7, 1IC6 and 1THM 1SH7 Number of ... hydrogen bonded The energetic cost of the dissolution of a protein under such conditions, arising from the unfavourable disruption of the optimized hydrogen bond network, may be offset by favourable ... combined amino acid substitutions aimed at increasing the stability of the Vibrio proteinase are being tested Elucidation of the Vibrio protein833 ´ ´ J Arnorsdottir et al Structural aspects of...

Ngày tải lên: 19/02/2014, 16:20

... interaction of the 1,3BPGA analogues at both Ps and Pi phosphate-binding sites Comparison of the inhibition of T cruzi and T brucei gGAPDHs Inhibition Table summarizes the inhibitory effects (IC50) of ... Inhibition and site-directed mutagenesis of T brucei gGAPDH In the absence of a 3D structure of a complex of T brucei gGAPDH with an analogue of 1,3-BPGA, we chose to investigate the enzyme–inhibitor ... described here, the inhibitor is present in only one of the four subunits of the enzyme This observation suggests that, in solution, the enzyme–inhibitor complexes have a distribution of populations...

Ngày tải lên: 20/02/2014, 02:21

... decarboxylase from brewer’s yeast Biomed Biochim Acta 47, 9–18 46 Baburina, I., Gao, Y., Hu, Z., Jordan, F., Hohmann, S & Furey, W (1994) Substrate activation of brewers’ yeast pyruvate decarboxylase ... ThDP-dependent enzymes One of these, the hydrogen bond between the N1¢ atom of the pyrimidine ring of ThDP and the side chain of an invariant glutamate residue of the neighbouring subunit (Glu52), is ... a role of this helix in closure of the active site [36] A model of the a-carbanion/enamine intermediate of the substrate indole-3-pyruvate with ThDP in the active site of IPDC was built based...

Ngày tải lên: 20/02/2014, 11:20

... [protein data bank (PDB) 3if5] [10], and glutaminases from E coli (PDB 1u60) [5], B subtilis (PDB 1mki, 3brm, 2osu) [5], Geobacillus kaustophilus (PDB 2pby) and human kidney (PDB 3czd) have been determined ... Figure shows a comparison of Table Displacement of the backbone atoms of Mglu and Bacillus glutaminase induced by ligand binding Displacement values for backbone atoms of the nonliganded and liganded ... structure of glutaminase from B subtilis (YbgJ, Bacillus glutaminase) with covalently bound 5-oxol-norleucine (PDB 3brm) reveals its Ser74 to be the catalytic nucleophile [5] On the basis of their...

Ngày tải lên: 06/03/2014, 09:22

... of NlpI These constitute the most distant interactions between elements of primary FEBS Journal 272 (2005) 166–179 ª 2004 FEBS structure, and include a hydrogen bond between the backbone carbonyl ... principally by the Of ces of Biological and Environmental Research and of Basic Energy Sciences of the US Department of Energy, and from the National Center for Research Resources of the National ... for new antibiotics Experimental procedures Fig Structural homologues of NlpI Structure alignment of NlpI (blue) with (A) p67phox and (B) domain III of MalT (yellow) Superimposition of coordinates...

Ngày tải lên: 07/03/2014, 16:20