Covalently bound hybrid

The covalently bound hybrid was prepared in the presence of Ca2+. Cross-linking experiments in the absence of Ca2+ were also performed using CaM and PDE. However, we could not obtain the hybrid between CaM and PDE in the fraction pattern without Ca2+. This finding suggests that the assembling of the present molecules requires that CaM is associated with the specific CaM binding domain of PDE when the two biomolecules are linked with remaining as much cooperatively as possible. 

The synthetic and plasmid DNAs are mixed and join their sticky ends spontaneously. They are covalently bound together by DNA ligases, when the resulting hybrid plasmid is inserted into bacterial cells. Dilute calcium chloride solutions render the bacterial membranes permeable and allow the passage of ONA into the cells. 

Nonlinear Optical Devices. A transparent, optically active, sol—gel-derived organic—inorganic glass has been synthesized (68). This hybrid consists of a 2,4-dinitroaminophenylpropyl-triethoxysilane covalently bound to a siUcon alkoxide-derived siUca network. This hybrid exhibits a strong electric field-induced second harmonic signal and showed no signs of crystallization. 

Most eukaryotic mRNA molecules have up to 250 adenine bases at their 3 end. These poly (A) tails can be used in the affinity chromatographic purification of mRNA from a total cellular RNA extract. Under high salt conditions, poly (A) will hybridize to oligo-dT-cellulose or poly(U)-sepharose. These materials are polymers of 10 to 20 deoxythymidine or uridine nucleotides covalently bound to a carbohydrate support. They bind mRNA containing poly (A) tails as short as 20 residues. rRNA and tRNA do not possess poly (A) sequences and will not bind. After washing the mRNA can be eluted with a low salt buffer. 

Ferrocene is composed of a pair of 6-7r-electron carbon arrays and a 6-d-electron iron(II) atom. Ferrocene-fullerene donor-acceptor dyads carry all the requisites for electron-transfer phenomena. However, data for the formation of ferrocene-fullerene hybrids are not abundant. Some such dyads have already been synthesized following the methodology of 1,3-dipolar cycloaddition of the appropriate azome-thine ylides to C60, with either variable-spacing building blocks or a rigid-bridge all-cj-bonded framework, in order to tune the redox properties of the system [40,234, 248-251]. Another novel dyad that contained two covalently bound ferrocene units was recently synthesized via cyclopropanation of the fullerene core [252]. 

Table III shows that the luminescent lifetimes and the relative luminescent intensities for the covalently bound duplex and its noncovalent analogue are similar. As with [Ru(phen)2(dppz)]2+, a biexponential decay in emission is observed for the ruthenated oligonucleotide hybridized to its complement. A small shift in the wavelength of maximum emission is also observed compared to the noncovalent complex. This shift likely reflects the sensitivity in emission to the stacking of the oriented dppz ligand a dependence of the maximum emission wavelength on base...

The luminescence of the hybridized [Ru(phen)2(dppz)]2+ derivative may be used to characterize the molecular assembly (77). Dilution experiments show that intercalation is intramolecular at concentrations <5 mM duplex addition of unmodified duplex to the covalently bound duplex results in <5% change in the luminescence. The results of experiments performed on duplexes containing mismatches in various positions along the duplex are also consistent with intramolecular intercalation. In this series, luminescence is higher for mismatches near the ruthenated end of the oligomer, where the ruthenium complex can intercalate intramolecularly and stabilize the mismatched site. 

Figure 6. Sequence of a 15-mer oligonucleotide bearing covalently bound rhodium(III) complex, hybridized to its 32P-labeled complement. Arrows point to the sites of photocleavage by the metal complex, establishing that it is intercalated either adjacent to the first (as shown) or second base steps from the site of covalent attachment.

With conventional chips, it is well known that thiolated-DNA can be easily immobilized on gold but does not interact by ordered self-assembly, due to nonspecific interactions between the DNA bases and the gold. Different alkanethiols have been used to improve the hybridization efficiency and the selectivity, followed by immobilization of thiolated-DNA on the substrate [59,61,69]. Hence, this method requires two steps and needs consideration concerning the experimental conditions. However, DNA-conjugated polymer does not only prevent desorption of probe DNA from the surface, because the DNA is covalently bound to the self-assembly polymer, but it also... 

DNA that was covalently bound to a polymer. The hybridized P-1 and P-2 DNA chains functioned as hydrophilic linkers in addition, they increased the negative electric charge density on the surface. For these reasons, our DNA-conjugated polymer-coated substrate showed better prevention of nonspecific hybridization of SNP sequences and was selective exclusively for fully matched DNA. 

The sp -type hybridized ionic acyiiminium species (60) are in chemical equilibrium with the corresponding covalently bound sp -type species (61 Scheme 29). ... 

Southern s technique could not be applied to the blot transfer of RNA separated by gel electrophoresis. Alwine et al. (A2) therefore devised a procedure in which RNA bands are blot transferred from the gel onto the chemically reactive paper, where they are bound covalently. The reactive paper is prepared by diazotization of aminobenzyl oxymethyl paper, which can be prepared from Whatman paper by a series of uncomplicated reactions. Once covalently bound, the RNA is available for hybridization with radiolabelled DNA probes. Hybridizing bands are detected autoradiographically. This method is termed Northern blotting. 

Chevrier, D., Rasmussen, S.R., and Guesdon, J. L. (1993) PCR product quantification by non radioactive hybridization procedures using an oligonucleotide covalently bound to microwells. Molecular and Cellular Probes, 7, 187 197. 

In the metal derivatives of phthalocyanine the metal atoms are coordinated by four atoms of nitrogen at the corners of a square, and this arrangement suggests that these atoms are bound by covalent dsp2 hybrid bonds. Such an explanation is acceptable in the case of the transition metals, which readily form dsp2 bonds, but cannot account for the existence of the beryllium compound. It is, however, notable in this connexion that this derivative is conspicuously less stable than the phthalocyanines of the other metals. 

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