Yang, DY, Chang TC, Sheu SY.
2007.
Interaction between human telomere and a carbazole derivative: A molecular dynamics simulation of a quadruplex stabilizer and telomerase inhibitor, Sep 27. Journal of Physical Chemistry A. 111:9224-9232., Number 38
AbstractThe mechanism of inhibition of telomerase by drugs is a key factor in an understanding of guanine-quadruplex complex stabilization during human cancer. This study describes a simulated annealing docking and molecular dynamics simulation to investigate a synthesized potent inhibitor, 3,6-bis(1-methyl-4-vinylpyridinium iodine) carbazole (BMVC), which stabilizes the quadruplex structure of the human telomeric DNA sequence d[AG(3)(T(2)AG(3))(3)] and inhibits telomerase activity. The compound was predicted to selectively interact with the quadruplex structure. During our simulation, the binding affinities were calculated and used to predict the best drug-binding sites as well as enhanced selectivity compared with other compounds. Our studies suggest that the simulation results quite coincide with the experimental results. In addition, molecular modeling shows that a 2:1 binding model involving the external binding of BMVC to both ends of the G-quartet of d[AG(3)(T(2)AG(3))(3)] is the most stable binding mode and this agrees with the absorbance titration results that show two binding sites. Of particular interest is that one pyridinium ring and carbazole moiety of the BMVC can stack well at the end of G-quartet. This implies that BMVC is a good human quadruplex stabilizer and also a good telomerase inhibitor.
Chang, TC, Yang YP, Huang KH, Chang CC, Hecht C.
2005.
Investigation of thionin-DNA interaction by satellite hole spectroscopy, May. Optics and Spectroscopy. 98:655-660., Number 5
AbstractThe interactions of the two tautomers of thionin dye with DNA have been investigated by using satellite hole burning spectroscopy. Similar features in the absorption and satellite hole spectra of thionin in the presence of calf thymus (CT) DNA and polynucleotides [d(GC)(6)](2) (GC) suggested that thionin preferentially binds to GC rather than polynucleotides [d(AT)(6)](2) (AT). Different binding effects of the two tautomers to DNA could be observed. While the imino form fully intercalates into the DNA base pairs, the amino form is only partially intercalated. In addition, a broad hole associated with an antihole appeared in the presence of DNA, particularly in GC base pairs. The coincidence of the antihole with the absorption band of the amino form showed that the amino form is the photoproduct of the imino form. An increase in intensity of the broad hole and its antihole and the loss of nonresonant hole intensity upon interaction with CT DNA could be described by rapid ground state recovery resulting from fast charge transfer between the intercalated thionin and a guanine base quenching the internal conversion. (c) 2005 Pleiades Publishing, Inc.
Kao, WC, Wang VCC, Huang YC, Yu SSF, Chang TC, Chan SI.
2008.
Isolation, purification and characterization of hemerythrin from Methylococcus capsulatus (Bath), Aug. Journal of Inorganic Biochemistry. 102:1607-1614., Number 8
AbstractEarlier work from our laboratory has indicated that a hemerythrin-like protein was over-produced together with the particulate methane monooxygenase (pMMO) when Methylococcus capsulatus (Bath) was grown under high copper concentrations. A homologue of hemerythrin had not previously been found in any prokaryote. To confirm its identity as a hemerythrin, we have isolated and purified this protein by ion-exchange, gel-filtration and hydrophobic interaction chromatography, and characterized it by mass spectrometry, UV-visible, CD, EPR and resonance Raman spectroscopy. On the basis of biophysical and multiple sequence alignment analysis, the protein isolated from M. capsulatus (Bath) is in accord with hemerythrins previously reported from higher organisms. Determination of the Fe content in conjunction with molecular-weight estimation and mass analysis indicates that the native hemerythrin in M. capsulatus (Bath) is a monomer with molecular mass 14.8 kDa, in contrast to hemerythrins from other eukaryotic organisms, where they typically exist as a tetramer or higher oligomers. (c) 2008 Elsevier Inc. All rights reserved.