Compact dimers

Control arrays with evenly spaced nucleosomes are disorganized by SWI/SNF compact dimers within these arrays could not be positively identified... 

A series of so-called compact dimers has also been described [4]. These compounds were characterized by an even three-dimensionally distributed hydrophilicity due to the perpendicular ring conformation, and stabiHzation of hydrophilicity by hydroxylated amido groups characterized by high energy rotational barriers for (E/Z) isomers. Furthermore, their viscosity was low, allowing injection at 350 mgl mL (at this concentration and at 20°C, their viscosities were found to be between 19 and 26 mPa.s vs 44.5 mPa.s for iodixanol) [4]. 

The dimeric form of fractalkine (Figure 3C) resembles a compact CC chemokine compared with the elongated form seen in Figure 2A. The first disulfide of fractalkine forces the N-terminal region to remain close to the core of the molecule (38). The interface between subunits is asymmetrical and involves a (3-strand from residues Cys-8 to Thr-11 from one monomer and residues Thr-11... 

The thiophosphate199 oxide, related to the dimeric hydroxide above, [Me2Sn(ytt-0H) 0(S)P(0Et2) ]20, has the compact multi-ring structure of (26a) [R = Me, Z =... 

The MBPs are extrinsic proteins localized exclusively at the cytoplasmic surface in the major dense line (Fig. 4-11), a conclusion based on their amino acid sequence, inaccessibility to surface probes and direct localization at the electron microscope level by immunocytochemistry. There is evidence to suggest that MBP forms dimers, and it is believed to be the principal protein stabilizing the major dense line of CNS myelin, possibly by interacting with negatively charged lipids. A severe hypomyelination and failure of compaction of the major dense line in MBP deficient shiverer mutants supports this hypothesis (Table 4-2). 

The formation of ER dimers can be favored once the first monomer has bound to the DNA, since this presents positive cooperation in binding the next monomer. In any case, DNA binding creates a greater compaction of the dimer that results in a subsequent spatial restructuring of the receptor molecules. 

The interaction between the receptor dimer and DNA is produced in an orderly manner. First, the dimer is placed in the main furrow of the double helix, and the first monomer interacts with the first pentamer of the HRE in the main furrow of the double helix. Later the second molecule of the receptor dimer binds to the second pentamer. The distance between both pentamers is minimum from zero to five nucleotides, depending on the type of receptor. This implies that the dimer assures a sufficiently compact and symmetrical structure among both receptor molecules, so that a similar intimacy can be produced in the association with the palindrome. 

Figure 9. The torsional potential of trifluoroethanol (dashed line, g+/t/g, in analogy to the ethanol case shown in Fig. 4) is only distorted slightly if it acts as a hydrogen bond acceptor toward a g+ trifluoroethanol unit [30] (full line). Nevertheless, only the compact inserted homochiral dimer (left, i c hom) is observed in the jet experiment, not the compact associated heterochiral dimer (right, a c het).

The H2a-H2b histone dimer also has strong salt-dependent conformational properties, with a transition near 0.5 M NaCl.(93) Above 0.5 M NaCl, the tyrosine fluorescence emission becomes less quenchable by Cs+, and the dimer structure becomes more compact. 

Despite many biochemical similarities between linker and core histones the proteins of these two groups differ in architecture, evolutionary origin, and function. Each of the four core histones has a characteristic histone fold domain. The latter is an old and ubiquitous structural motif used in DNA compaction and protein dimerization [3]. Linker histones do not have a histone fold. The canonical... 

By carefully adjusting the distances between two sialoside residues in a number of divalent clusters. Click and Knowles [105] have obtained dimer 104 having the two sialic acid 5.7 nm apart. Compound 104 was 100-fold more potent than methyl a-sialoside (Neu5Aca2Me) in influenza virus inhibitions and 500-fold more potent in the case of polyomia virus. Alternatively, sialyl-a-(2,6)-/3-LacNAc dimers (105) branched at different positions of synthetic peptides, including compact glycine-rich and helical proline-rich peptides, afforded clusters which were only 8- and 4-fold more potent, respectively, than the corresponding monovalent trisaccharide [106]. 

The results presented in this work show that in the linear structured water dimer the partitioned energy terms calculated for the proton donor and acceptor molecules are significantly different (except the kinetic energy). The electron structure of the proton donor molecule was found more compact than that of the acceptor subsystem, when compared their (partitioned) total energy EM values. This result is in an excellent agreement with our pre-vious results obtained on the separated molecular orbital energies [17]. 

Large negative values of Av (-25 to -50 cm3/mol) have been found in the investigation of Diels-Alder reactions, such as the dimerization of cyclopentadiene (Table 3.2-1, b). The cyclic transition state has a compact structure similar to the reaction products. Av is only a little smaller than the volume change between the initial- and the product-structures, indicating a late transition state. 

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