Hybrid complexes

No cross-linking was observed when noncomplementary rather than complementary DNA was added to the mixture, and thus interstrand transfer of QM appears to be effective only from within a hybridized complex. Despite the obvious complications of annealing DNA that is constrained by capture of both QM equivalents of QMP11, such a species is suggested since both QM sites require protection from irreversible reaction over the many hours in which the cross-linking activity is preserved. 

Fig. 14.3. Stoichiometry of phosphorylation/inactivation of the bovine kidney and A. suum E1 isoforms. Adult A. suum PDC was depleted of its E1 component and reconstituted with either bovine kidney E1 or recombinant A. suum E1s containing either the al or all isoform (Klingbeil etal., 1997 Huang etal., 1998b). The hybrid complexes were then assayed for PDC activity and the incorporation of 32P, as described fully in Thissen etal. (1986). Upper panel o, bovine kidney E1 , E1 isolated directly from the adult A. suum PDC. Lower panel , A. suum E1al isoform , A. suum E1all isoform.

Sakaguchi N, Kojima C, Harada A, Koiwai K, Kono K (2008) The correlation between fusion capability and transfection activity in hybrid complexes of lipoplexes and pH-sensitive liposomes. Biomaterials 29 4029 1036... 

Ogawa, Koshihara, Takesada and Ishikawa (2002) New class of photo-induced cooperative phenomena in organic and inorganic hybrid complexes [253],... 

Fischer-Tropsch catalysis, 38 333-334 reaction with metal oxides, 38 311-314 anionic hybrid complex, 38 312 butterfly cluster, 38 312-313... 

This report was the first of its type to show the ability of such a large covalently linked carbohydrate (neomycin) to aid in RNA-DNA hybrid complex-ation. N-Neo-conjugate and a 7-base-long RNA sequence present in a-sarcin loop can form a stable hybrid duplex. The stability of a hybrid duplex with addition of one neomycin equivalent is comparable to the stability of a hybrid duplex where the DNA has a covalent bond to neomycin. The presence of a single mismatch decreases the melting temperature of both neomycin-conjugated... 

D-P-Man high mannose bisected hybrid complex bisected complex... 

Agars, including highly substituted agaran—agarose hybrids Typical carrageenans and DL-hybrids Complex sulfated galactans (DL-hybrids)... 

Confirmation has come through crystallographic studies of oxalate binding to lactoferrin. The crystal structure of a hybrid complex of copper-lactoferrin, at 2.2-A resolution, has carbonate in the N-termi-nal site and oxalate in the C-terminal site (192). The oxalate ion is bound to the metal ion (Cu2+ in this case) in 1,2-bidentate mode, as anticipated (190,191), i.e., through both carboxylates (Fig. 26a). One... 

Distinct differences are also seen when anions other than C032 are used. The crystal structure of oxalate-substituted diferric lactoferrin shows differences in the anion binding in the two sites in the C-site the oxalate is symmetric bidentate, whereas in the N-site it is asymmetric (193). When Cu2+ is the metal ion the oxalate binding differences become even more pronounced. Copper-transferrin binds oxalate only in its N-terminal site (91). Copper-lactoferrin and copper-ovotransfer-rin each bind two oxalate ions but binding occurs preferentially in the C-lobe (157,192). These different affinities mean that hybrid complexes can be prepared with oxalate in one site and carbonate in the other (92, 157, 192). The use of oxalate as synergistic anion gives rise to spectroscopically distinct sites for other metal ions also (171). 

Pope, S.J.A., Coe, B.J., Faulkner, S., et al. (2004) Self-assembly of heterobimetalhc d-f hybrid complexes sensitization of lanthanide luminescence by d-block metal-to-Ugand charge-transfer excited states. Journal of the American Chemical Society, 126, 9490. 

Montalti, M., Rrodi, L., Zaccheroni, N., et al. (2001) A luminescent anion sensor based on a europium hybrid complex. Journal of the American Chemical Society, 123, 12694-12695. 

The varying thiostrepton sensitivity of different archaea appears to be accounted for by the presence or the absence of an Lll-like protein, rather than by primary structural features of the archaeal 23S rRNA [153]. Firstly, all of the sequenced archaeal 23S RNAs possess the prerequisite A residue at the 1067-equivalent position [154]. Secondly, hybrid complexes formed by 23 S rRNA of (the thiostrepton-insensitive) S. solfataricus and LI 1 proteins of (the thiostrepton-sensitive) E. coli bind the drug with high affinity [153]. Thirdly, the thiostrepton-binding capacity of ribosomes from M. formicicum, which are sensitive to thiostrepton, but less so than either E. coli or M vannielii ribosomes, can be significantly enhanced by the addition of E. coli protein LI 1 in contrast, no enhancement... 

Zakrzewska-Trznadel, G., Radioactive solutions treatment by hybrid complexation—UF/NF process, J. Membr. Sci., 225, 25, 2003. International Atomic Energy Agency, Advances in Technologies for Treatment of Low and Intermediate Level Radioactive Liquid Wastes, Technical Report Series No. 370, IAEA, Vienna, 1994. 

Many DNA-based biosensors (genosensors) are based on the ability of complementary nucleic acid strands to selectively form hybrid complexes. The complementary strands anneal to one another in a Watson-Crick manner of base pairing. Hybridization methods used today, such as microhtre plates or gel-based methods, are usually quite slow, requiring hours to days to produce reliable results, as described by Keller and Manak [10]. Biosensors offer a promising alternative for much faster hybridization assays. 

Figure 4-15 Examples of DNA biosensor configurations (A) direct electrooxidation detection of guanosine bases in target DNA after hybridization with immobilized capture probe on electrode surface (B) electrochemical detection of hybridization using exogenous redox species that intercalates into hybridized complex between immobilized capture DNA probe and target DNA.

In a similar [4+2] reaction of a, -unsaturated esters, the aluminum catalyst complexed with the ligand S-VAPOL resulted in autoinduction , because of cooperative interaction of the product with the catalyst to generate a more selective catalytic species (Scheme 6.48) [68]. The ee% gradually increased as the reaction time lengthened. In the proposed intermediate, penta-coordinated aluminum complex 77, the cycloadduct is recognized as a complementary ligand, leading to substantial asymmetric induction. The acrylate is activated effectively within this hybridized complex which adopts pentacoordination [87]. 

Attention has been focused on four different chemiluminescent systems, two as substrates for enzymes and two as labels incorporated in the probes (activated after hybridization by H2O2/alkali (Table 7.6)), The latter are usually intended for diagnostic purposes and prepared by commercial suppliers, whereas those serving as a substrate for enzymes attached to the probe-hybrid complex can be readily adapted for many hybridization assays. 

Central to secondary label systems is the strategy chosen to introduce the primary label into the hybrid complex. Most approaches rely on the introduction of small modifications in the probe to avoid interference during hybridization. The two major secondary label/detec-tion systems are biotin/streptavidin and hapten/antibody, whereas... 

Hong, A. P., S. D. Boyce, and M. R. Hoffmann (in press), Catalytic Autoxidation of Chemical Contaminants by Hybrid Complexes of Co(II) Phthalocyanine, Environ. Sci. Technol. 23. 

The presence of an actual water molecule coordinated to Z, when the anion contains two hydrogen atoms, was first demonstrated (55) for the SiConWn and SiComWn anions. The water in the first was shown to be replaceable by pyridine, and in the second by pyridine and ammonia. Crystalline salts of the product anions were isolated. The phenomenon seems to be a general one for XZWn anions containing Co (II) (55, 213), Co(III) (55, 203, 213), Ni(II) (55, 213), and Cr(III) (222). As predicted (55), it has also been observed for the X2C0W17 anions (176). These anions and their substitution products therefore constitute a class of hybrid complexes, intermediate between normal heteropolyanions with metal heteroatoms and conventional coordination complexes, and the significance of this has been discussed elsewhere (55). 

Fig. 5. Sandwich-hybridization assay (A) A biotinylated DNA oligonucleotide, which is complementary to one portion of the target sequence, is mixed with streptavidin and applied to form the capture zone 1.5 cm from the base of the membrane. An unmodified DNA oligonucleotide, which is complementary to the reporter probe sequence on the liposomes, is applied to form the control zone 2.5cm from the base of the membrane. (B) In the presence of target, a sandwich hybridization complex forms with dye-encapsulating liposomes resulting in a magenta-colored band at the capture zone. (C) In the absence of target, only the control band is visible as no sandwich complex has formed.

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