Structural properties of single lambda DNA treated with anti-cancer drug cisplatin were studied with magnetic tweezers and AFM. Under the effect of low-concentration cisplatin, the DNA became more flexible, with the persistence length decreased significantly from approximately 52 to 15 nm. At a high drug concentration, a DNA condensation phenomenon was observed. Based on experimental results fr...

Functionally active 70S ribosomes containing 4-thiouridine (s4U) in place of uridine were prepared by a formerly described in vivo substitution method. Proteins were crosslinked to RNA by 366 nm photoactivation of s4U. We observe the systematic and characteristic formation of 30S dimers; they were eliminated for analysis of RNA-protein crosslinks. M13 probes containing rDNA inserts complementar...

The reaction between RNA and 4'hydroxymethyl-4,5',8-trimethylpsoralen has been studied. Both natural RNA and synthetic RNAs were used. The base specificity of the reaction was found to be the same in natural RNA, homopolymers, and mononucleotides. Uridine was found to be the most reactive base in all cases. The kinetics of formation and reversal of monoadducts and crosslinks has been examined. ...

Shear relaxation and dynamic density fluctuations are studied within a Rouse model, generalized to include the effects of permanent random crosslinks. We derive an exact correspondence between the static shear viscosity and the resistance of a random resistor network. This relation allows us to compute the static shear viscosity exactly for uncorrelated crosslinks. For more general percolation ...

In this manuscript we report the crosslinking of pre-existing macromolecules in solution through the use of photoactive benzophenone chromophores. We show that a bifunctional crosslinker composed of two benzophenone chromophores as well as a single benzophenone chromophore crosslink poly (butadiene) and poly (ethylene oxide) in solution to form insoluble gels when irradiated with UV light. The ...

OBJECTIVE To establish if urinary excretion rates of the collagen crosslinks pyridinoline and deoxypyridinoline, which are known to be elevated in established rheumatoid arthritis (RA), are useful markers of bone loss in this disease. METHODS Eight hour urine collections on all patients and 52 controls were performed, and the rates of pyridinoline and deoxypyridinoline excretion were measured...

Dynamic covalent materials are stable materials that possess reversible behaviour triggered by stimuli such as light, redox conditions or temperature; whereas supramolecular crosslinks depend on the equilibrium constant and relative concentrations of crosslinks as a function of temperature. The combination of these two reversible chemistries can allow access to materials with unique properties....

The repair mechanisms acting on DNA interstrand crosslinks (ICLs) in eukaryotes are poorly understood. Here, we provide evidence for a pathway of ICL processing that uses components from both nucleotide excision repair (NER) and translesion synthesis (TLS) and predominates during the G1 phase of the yeast cell cycle. Our results suggest that repair is initiated by the NER apparatus and is follo...