Binding to Biomolecules

While open-chain cyanines such as Cy5, Cy5.5, or Alexa 647 typically exhibit small fluorescence lifetime changes upon binding to biomolecules, squaraine dyes, in general, demonstrate pronounced lifetime changes upon binding to large-molecular-weight analytes [17, 18], which can be used for FLT-based assays. 

Pullman, A., and H. Berthod. 1976. Cation Binding to Biomolecules. The Screening of the Electrostatic Potential of the Phosphate Group by Mono- and Divalent Cations. Chem. Phys. Lett. 41, 205. 

The above historical outline refers mainly to the EPR of transition ions. Key events in the development of radical bioEPR were the synthesis and binding to biomolecules of stable spin labels in 1965 in Stanford (e.g., Griffith and McConnell 1966) and the discovery of spin traps in the second half of the 1960s by the groups of M. Iwamura and N. Inamoto in Tokyo A. Mackor et al. in Amsterdam and E. G. Janzen and B. J. Blackburn in Athens, Georgia (e.g., Janzen 1971), and their subsequent application in biological systems by J. R. Harbour and J. R. Bolton in London, Ontario (Harbour and Bolton 1975). 

It was conclusively shown that deoxychlordiazepoxide (393) had none of the phototoxic properties of the parent drug, at least in the rat [225]. Chlordiazepoxide, demethylchlordiazepoxide, demoxepam and diazepam-4-oxide were all phototoxic to a bacterial cell preparation. There was a close relationship between the phototoxicities of the A-oxides and the toxicity in the dark of their oxaziridines. The reduced forms of the four compounds were not phototoxic [ 228 ]. Kinetic studies demonstrated that the oxaziridine (390) covalently bonds to plasma proteins. The half-life of the oxaziridine in the presence of high concentrations of protein was about 30 min. It therefore has time not only to bind to biomolecules in the skin surface, but also to attack internal organs. This was put forward as the explanation of previously observed kidney and liver damage in the rat [229]. 

Additional assays used in early pharmaceutical property profiles usually include plasma protein binding, individual cytochrome P450 assays, stability in the presence of serum, production of metabolites likely to be involved in covalent binding to biomolecules, and interaction with efflux pumps ... 

Bifunctional linkers bearing functional groups like thiols, disulfides or phosphines are widely used for covalent binding between Au NPs and biomolecules. For example, Au NPs stabilized with a functionalized polysiloxane shell have been used for covalent binding to biomolecules [152]. 

Excess copper is toxic to cells. On one hand, copper ions can avidly bind to biomolecules by ligand interaction with cysteines or by binding to histidine-rich regions. Copper ions could also be incorporated into proteins instead of zinc or other metal ions during biosynthesis. On the other hand, copper ions can form radicals by a Fenton-type reaction as shown in Eq. (1) ... 

As indicated in the introduction, it is possible to carry out PAC experiments under physiological conditions, and even in vivo experiments are possible. One example of the latter is the study of the fast inhibition of photosynthesis in cyanobacteria. Photosynthesis in cyanobacteria is inhibited within about 15 min after exposure to Cd(II). Exposing the cyanobacteria to " "Cd it was possible to follow the fate of Cd(II) in terms of binding to biomolecules, as the biological... 

Recent trend in biosensor manufacturing is to use synthetic procedures to incorporate a label indicative of a change in a physicochemical property upon binding to biomolecule. An example is the preparation of a novel, fluorescently active, carboxylic acid derivative of 2-pyridylazo compounds (PAR) [186]. 

Is lead binding to biomolecules under thermodynamic or kinetic control ... 

How much of this lead is bioavailable (i.e., thermodynamically and kinetically accessible and hence able to bind to biomolecules) ... 

The fluorescence enhancement of flavonols upon binding to biomolecules has been recently exploited for the development of analytical methods and in microfluorescence studies using flavonols as endogenous fluorophores." In particular, the use of quercetin and other flavonols as probes in vim for target proteins has been reported by Gutzeit et... 

J. Mueller and K. Johnston, Ag(I), Pb(II) and Hg(II) Binding to Biomolecules Studied by Perturbed Angular Correlation of y-Rays (PAC) Spectroscopy Function and Toxicity of Metal Ions in Biological Systems , CERN Document Server Preprints, Avail. URL http //cdsweb.cem.ch/record/1156119/files/ INTC-P-259.pdf... 

Some work was reported on the World Wide Web [82]. Researchers have been working on developing fluorescent probes where markers covalently bind to biomolecules. The penetrating power of NIR light is the driving force behind this research. 

R. Cingolani, and G. Gigli, J. Phys. Chem. B, 110, 18651 (2006). Optical Properties of N-Succinimidyl Bithiophene and the Effects of the Binding to Biomolecules Comparison between Coupled-Cluster and Time-Dependent Density Functional Theory Calculations and Experiments. 

Lund M, Heyda J, Jungwirth P. (2010) Ion binding to biomolecules. In Kunz W (ed.), Specijk Ion Effects, Chap. 8. World Scientific Publishing, Singapore. Ashcroft NW, Mermin ND. (1976) Solid State Physics. Thomson Learning. Bockris JOM. (1959) Modern Aspects of Electrochemistry, 2nd ed., Butterworth, London. 

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